/******************************************************************************
 *
 * Project:  GeoPackage Translator
 * Purpose:  Implements GDALGeoPackageDataset class
 * Author:   Paul Ramsey <pramsey@boundlessgeo.com>
 *
 ******************************************************************************
 * Copyright (c) 2013, Paul Ramsey <pramsey@boundlessgeo.com>
 * Copyright (c) 2014, Even Rouault <even dot rouault at mines-paris dot org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "ogr_geopackage.h"
#include "ogr_p.h"
#include "swq.h"
#include "gdalwarper.h"
#include "ogrgeopackageutility.h"
#include "ogrsqliteutility.h"
#include "vrt/vrtdataset.h"

#include <cstdlib>

#include <algorithm>

CPL_CVSID("$Id: ogrgeopackagedatasource.cpp 3189229c71a9620126f6b349f4f80399baeaf528 2019-04-20 20:33:36 +0200 Even Rouault $")

// Keep in sync prototype of those 2 functions between gdalopeninfo.cpp,
// ogrsqlitedatasource.cpp and ogrgeopackagedatasource.cpp
void GDALOpenInfoDeclareFileNotToOpen(const char* pszFilename,
                                       const GByte* pabyHeader,
                                       int nHeaderBytes);
void GDALOpenInfoUnDeclareFileNotToOpen(const char* pszFilename);

/************************************************************************/
/*                             Tiling schemes                           */
/************************************************************************/

typedef struct
{
    const char* pszName;
    int         nEPSGCode;
    double      dfMinX;
    double      dfMaxY;
    int         nTileXCountZoomLevel0;
    int         nTileYCountZoomLevel0;
    int         nTileWidth;
    int         nTileHeight;
    double      dfPixelXSizeZoomLevel0;
    double      dfPixelYSizeZoomLevel0;
} TilingSchemeDefinition;

static const TilingSchemeDefinition asTilingShemes[] =
{
    /* See http://portal.opengeospatial.org/files/?artifact_id=35326 (WMTS 1.0), Annex E.3 */
    { "GoogleCRS84Quad",
      4326,
      -180.0, 180.0,
      1, 1,
      256, 256,
      360.0 / 256, 360.0 / 256 },

    /* See http://portal.opengeospatial.org/files/?artifact_id=35326 (WMTS 1.0), Annex E.4 */
    { "GoogleMapsCompatible",
      3857,
      -(156543.0339280410*256) /2, (156543.0339280410*256) /2,
      1, 1,
      256, 256,
      156543.0339280410, 156543.0339280410 },

    /* See InspireCRS84Quad at http://inspire.ec.europa.eu/documents/Network_Services/TechnicalGuidance_ViewServices_v3.0.pdf */
    /* This is exactly the same as PseudoTMS_GlobalGeodetic */
    { "InspireCRS84Quad",
      4326,
      -180.0, 90.0,
      2, 1,
      256, 256,
      180.0 / 256, 180.0 / 256 },

    /* See global-geodetic at http://wiki.osgeo.org/wiki/Tile_Map_Service_Specification */
    { "PseudoTMS_GlobalGeodetic",
      4326,
      -180.0, 90.0,
      2, 1,
      256, 256,
      180.0 / 256, 180.0 / 256 },

    /* See global-mercator at http://wiki.osgeo.org/wiki/Tile_Map_Service_Specification */
    { "PseudoTMS_GlobalMercator",
      3857,
      -20037508.34, 20037508.34,
      2, 2,
      256, 256,
      78271.516, 78271.516 },
};

static const char* pszCREATE_GPKG_GEOMETRY_COLUMNS =
    "CREATE TABLE gpkg_geometry_columns ("
    "table_name TEXT NOT NULL,"
    "column_name TEXT NOT NULL,"
    "geometry_type_name TEXT NOT NULL,"
    "srs_id INTEGER NOT NULL,"
    "z TINYINT NOT NULL,"
    "m TINYINT NOT NULL,"
    "CONSTRAINT pk_geom_cols PRIMARY KEY (table_name, column_name),"
    "CONSTRAINT uk_gc_table_name UNIQUE (table_name),"
    "CONSTRAINT fk_gc_tn FOREIGN KEY (table_name) REFERENCES gpkg_contents(table_name),"
    "CONSTRAINT fk_gc_srs FOREIGN KEY (srs_id) REFERENCES gpkg_spatial_ref_sys (srs_id)"
    ")";

/* Only recent versions of SQLite will let us muck with application_id */
/* via a PRAGMA statement, so we have to write directly into the */
/* file header here. */
/* We do this at the *end* of initialization so that there is */
/* data to write down to a file, and we will have a writable file */
/* once we close the SQLite connection */
OGRErr GDALGeoPackageDataset::SetApplicationAndUserVersionId()
{
    CPLAssert( hDB != nullptr );

    // PRAGMA application_id available since SQLite 3.7.17
#if SQLITE_VERSION_NUMBER >= 3007017
    const char *pszPragma = CPLSPrintf(
        "PRAGMA application_id = %u;"
        "PRAGMA user_version = %u",
        m_nApplicationId,
        m_nUserVersion);
    return SQLCommand(hDB, pszPragma);
#else
    CPLAssert( m_pszFilename != NULL );

#ifdef SPATIALITE_412_OR_LATER
    FinishNewSpatialite();
#endif
    /* Have to flush the file before f***ing with the header */
    CloseDB();

    size_t szWritten = 0;

    /* Open for modification, write to application id area */
    VSILFILE *pfFile = VSIFOpenL( m_pszFilename, "rb+" );
    if( pfFile == NULL )
        return OGRERR_FAILURE;
    VSIFSeekL(pfFile, knApplicationIdPos, SEEK_SET);
    const GUInt32 nApplicationIdMSB = CPL_MSBWORD32(m_nApplicationId);
    szWritten = VSIFWriteL(&nApplicationIdMSB, 1, 4, pfFile);
    if (szWritten == 4 )
    {
        VSIFSeekL(pfFile, knUserVersionPos, SEEK_SET);
        const GUInt32 nVersionMSB = CPL_MSBWORD32(m_nUserVersion);
        szWritten = VSIFWriteL(&nVersionMSB, 1, 4, pfFile);
    }

    VSIFCloseL(pfFile);

    /* If we didn't write out exactly four bytes, something */
    /* terrible has happened */
    if ( szWritten != 4 )
    {
        return OGRERR_FAILURE;
    }

    /* And re-open the file */
    if( !OpenOrCreateDB(SQLITE_OPEN_READWRITE) )
        return OGRERR_FAILURE;

    return OGRERR_NONE;
#endif
}

bool GDALGeoPackageDataset::ReOpenDB()
{
    CPLAssert( hDB != nullptr );
    CPLAssert( m_pszFilename != nullptr );

#ifdef SPATIALITE_412_OR_LATER
    FinishNewSpatialite();
#endif
    CloseDB();

    /* And re-open the file */
    return OpenOrCreateDB(SQLITE_OPEN_READWRITE);
}

/* Returns the first row of first column of SQL as integer */
OGRErr GDALGeoPackageDataset::PragmaCheck(
    const char * pszPragma, const char * pszExpected, int nRowsExpected )
{
    CPLAssert( pszPragma != nullptr );
    CPLAssert( pszExpected != nullptr );
    CPLAssert( nRowsExpected >= 0 );

    char **papszResult = nullptr;
    int nRowCount = 0;
    int nColCount = 0;
    char *pszErrMsg = nullptr;

    int rc = sqlite3_get_table(
        hDB,
        CPLSPrintf("PRAGMA %s", pszPragma),
        &papszResult, &nRowCount, &nColCount, &pszErrMsg );

    if( rc != SQLITE_OK )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Unable to execute PRAGMA %s: %s", pszPragma,
                  pszErrMsg ? pszErrMsg : "(null)" );
        sqlite3_free( pszErrMsg );
        return OGRERR_FAILURE;
    }

    if ( nRowCount != nRowsExpected )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "bad result for PRAGMA %s, got %d rows, expected %d",
                  pszPragma, nRowCount, nRowsExpected );
        sqlite3_free_table(papszResult);
        return OGRERR_FAILURE;
    }

    if ( nRowCount > 0 && ! EQUAL(papszResult[1], pszExpected) )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "invalid %s (expected '%s', got '%s')",
                  pszPragma, pszExpected, papszResult[1]);
        sqlite3_free_table(papszResult);
        return OGRERR_FAILURE;
    }

    sqlite3_free_table(papszResult);

    return OGRERR_NONE;
}

static OGRErr GDALGPKGImportFromEPSG(OGRSpatialReference *poSpatialRef,
                                     int nEPSGCode)
{
    CPLPushErrorHandler(CPLQuietErrorHandler);
    const OGRErr eErr = poSpatialRef->importFromEPSG(nEPSGCode);
    CPLPopErrorHandler();
    CPLErrorReset();
    return eErr;
}

OGRSpatialReference* GDALGeoPackageDataset::GetSpatialRef(int iSrsId)
{
    /* Should we do something special with undefined SRS ? */
    if( iSrsId == 0 || iSrsId == -1 )
    {
        return nullptr;
    }

    std::map<int, OGRSpatialReference*>::const_iterator oIter =
                                                m_oMapSrsIdToSrs.find(iSrsId);
    if( oIter != m_oMapSrsIdToSrs.end() )
    {
        if( oIter->second == nullptr )
            return nullptr;
        oIter->second->Reference();
        return oIter->second;
    }

    CPLString oSQL;
    oSQL.Printf( "SELECT definition, organization, organization_coordsys_id%s "
                 "FROM gpkg_spatial_ref_sys WHERE definition IS NOT NULL AND "
                 "srs_id = %d LIMIT 2",
                 m_bHasDefinition12_063 ? ", definition_12_063" : "",
                 iSrsId );

    SQLResult oResult;
    OGRErr err = SQLQuery(hDB, oSQL.c_str(), &oResult);

    if ( err != OGRERR_NONE || oResult.nRowCount != 1 )
    {
        SQLResultFree(&oResult);
        CPLError( CE_Warning, CPLE_AppDefined,
                  "unable to read srs_id '%d' from gpkg_spatial_ref_sys",
                  iSrsId);
        m_oMapSrsIdToSrs[iSrsId] = nullptr;
        return nullptr;
    }

    const char *pszWkt = SQLResultGetValue(&oResult, 0, 0);
    const char* pszOrganization = SQLResultGetValue(&oResult, 1, 0);
    const char* pszOrganizationCoordsysID = SQLResultGetValue(&oResult, 2, 0);
    const char *pszWkt2 = m_bHasDefinition12_063 ? SQLResultGetValue(&oResult, 3, 0) : nullptr;
    if( pszWkt2 && !EQUAL(pszWkt2, "undefined") )
        pszWkt = pszWkt2;

    OGRSpatialReference *poSpatialRef = new OGRSpatialReference();
    poSpatialRef->SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
    // Try to import first from EPSG code, and then from WKT
    if( !(pszOrganization && pszOrganizationCoordsysID
          && EQUAL(pszOrganization, "EPSG") &&
          GDALGPKGImportFromEPSG(poSpatialRef, atoi(pszOrganizationCoordsysID))
          == OGRERR_NONE) &&
        poSpatialRef->SetFromUserInput(pszWkt) != OGRERR_NONE )
    {
        CPLError( CE_Warning, CPLE_AppDefined,
                  "Unable to parse srs_id '%d' well-known text '%s'",
                iSrsId, pszWkt);
        SQLResultFree(&oResult);
        delete poSpatialRef;
        m_oMapSrsIdToSrs[iSrsId] = nullptr;
        return nullptr;
    }

    SQLResultFree(&oResult);
    m_oMapSrsIdToSrs[iSrsId] = poSpatialRef;
    poSpatialRef->Reference();
    return poSpatialRef;
}

const char * GDALGeoPackageDataset::GetSrsName(
    const OGRSpatialReference& oSRS )
{
    const char* pszName = oSRS.GetName();
    if( pszName )
        return pszName;

    // Something odd.  Return empty.
    return "Unnamed SRS";
}

/* Add the definition_12_063 column to an existing gpkg_spatial_ref_sys table */
bool GDALGeoPackageDataset::ConvertGpkgSpatialRefSysToExtensionWkt2()
{
    SQLResult oResultTable;
    OGRErr eErr = SQLQuery(hDB,
        "SELECT srs_name, srs_id, organization, organization_coordsys_id, definition, description FROM gpkg_spatial_ref_sys LIMIT 100000"
        , &oResultTable);
    if( eErr != OGRERR_NONE )
        return false;

    bool bRet = SoftStartTransaction() == OGRERR_NONE;

    if( bRet )
    {
        bRet = SQLCommand(hDB,
               "CREATE TABLE gpkg_spatial_ref_sys_temp ("
               "srs_name TEXT NOT NULL,"
               "srs_id INTEGER NOT NULL PRIMARY KEY,"
               "organization TEXT NOT NULL,"
               "organization_coordsys_id INTEGER NOT NULL,"
               "definition TEXT NOT NULL,"
               "description TEXT, "
               "definition_12_063 TEXT NOT NULL)") == OGRERR_NONE;
    }

    if( bRet )
    {
        for( int i = 0; bRet && i < oResultTable.nRowCount; i++ )
        {
            const char* pszSrsName = SQLResultGetValue(&oResultTable, 0, i);
            const char* pszSrsId = SQLResultGetValue(&oResultTable, 1, i);
            const char* pszOrganization = SQLResultGetValue(&oResultTable, 2, i);
            const char* pszOrganizationCoordsysID = SQLResultGetValue(&oResultTable, 3, i);
            const char* pszDefinition = SQLResultGetValue(&oResultTable, 4, i);
            const char* pszDescription = SQLResultGetValue(&oResultTable, 5, i);
            char* pszSQL;

            OGRSpatialReference oSRS;
            if( pszOrganization && pszOrganizationCoordsysID &&
                EQUAL(pszOrganization, "EPSG") )
            {
                oSRS.importFromEPSG(atoi(pszOrganizationCoordsysID));
            }
            if( !oSRS.IsEmpty() && pszDefinition && !EQUAL(pszDefinition, "undefined") )
            {
                oSRS.SetFromUserInput(pszDefinition);
            }
            char* pszWKT2 = nullptr;
            if( !oSRS.IsEmpty() )
            {
                const char* const apszOptionsWkt2[] = { "FORMAT=WKT2_2015", nullptr };
                oSRS.exportToWkt( &pszWKT2, apszOptionsWkt2 );
                if( pszWKT2 && pszWKT2[0] == '\0' )
                {
                    CPLFree(pszWKT2);
                    pszWKT2 = nullptr;
                }
            }
            if( pszWKT2 == nullptr )
            {
                pszWKT2 = CPLStrdup("undefined");
            }

            if( pszDescription )
            {
                pszSQL = sqlite3_mprintf(
                "INSERT INTO gpkg_spatial_ref_sys_temp(srs_name, srs_id, "
                "organization, organization_coordsys_id, definition, "
                "description, definition_12_063) VALUES ('%q', '%q', '%q', "
                "'%q', '%q', '%q', '%q')",
                pszSrsName, pszSrsId, pszOrganization, pszOrganizationCoordsysID,
                pszDefinition, pszDescription, pszWKT2);
            }
            else
            {
                pszSQL = sqlite3_mprintf(
                "INSERT INTO gpkg_spatial_ref_sys_temp(srs_name, srs_id, "
                "organization, organization_coordsys_id, definition, "
                "description, definition_12_063) VALUES ('%q', '%q', '%q', "
                "'%q', '%q', NULL, '%q')",
                pszSrsName, pszSrsId, pszOrganization, pszOrganizationCoordsysID,
                pszDefinition, pszWKT2);
            }

            CPLFree(pszWKT2);
            bRet &= SQLCommand(hDB, pszSQL) == OGRERR_NONE;
            sqlite3_free(pszSQL);
        }
    }
    SQLResultFree(&oResultTable);

    if( bRet )
    {
        bRet = SQLCommand(hDB, "DROP TABLE gpkg_spatial_ref_sys") == OGRERR_NONE;
    }
    if( bRet )
    {
        bRet = SQLCommand(hDB, "ALTER TABLE gpkg_spatial_ref_sys_temp RENAME TO gpkg_spatial_ref_sys") == OGRERR_NONE;
    }
    if( bRet )
    {
        bRet = OGRERR_NONE == CreateExtensionsTableIfNecessary() &&
               OGRERR_NONE == SQLCommand(hDB,
        "INSERT INTO gpkg_extensions "
        "(table_name, column_name, extension_name, definition, scope) "
        "VALUES "
        "('gpkg_spatial_ref_sys', 'definition_12_063', 'gpkg_crs_wkt', 'http://www.geopackage.org/spec120/#extension_crs_wkt', 'read-write')");
    }
    if( bRet )
    {
        SoftCommitTransaction();
        m_bHasDefinition12_063 = true;
    }
    else
    {
        SoftRollbackTransaction();
    }

    return bRet;
}

int GDALGeoPackageDataset::GetSrsId(const OGRSpatialReference& oSRS)
{
    OGRSpatialReference *poSRS = oSRS.Clone();

    const char* pszAuthorityName = poSRS->GetAuthorityName( nullptr );

    if ( pszAuthorityName == nullptr || strlen(pszAuthorityName) == 0 )
    {
        // Try to force identify an EPSG code.
        poSRS->AutoIdentifyEPSG();

        pszAuthorityName = poSRS->GetAuthorityName(nullptr);
        if (pszAuthorityName != nullptr && EQUAL(pszAuthorityName, "EPSG"))
        {
            const char* pszAuthorityCode = poSRS->GetAuthorityCode(nullptr);
            if ( pszAuthorityCode != nullptr && strlen(pszAuthorityCode) > 0 )
            {
                /* Import 'clean' SRS */
                poSRS->importFromEPSG( atoi(pszAuthorityCode) );

                pszAuthorityName = poSRS->GetAuthorityName(nullptr);
            }
        }
    }

    // Check whether the EPSG authority code is already mapped to a
    // SRS ID.
    char *pszSQL = nullptr;
    int nSRSId = DEFAULT_SRID;
    int nAuthorityCode = 0;
    OGRErr err = OGRERR_NONE;
    bool bCanUseAuthorityCode = false;
    if ( pszAuthorityName != nullptr && strlen(pszAuthorityName) > 0 )
    {
        // For the root authority name 'EPSG', the authority code
        // should always be integral
        nAuthorityCode = atoi( poSRS->GetAuthorityCode(nullptr) );

        pszSQL = sqlite3_mprintf(
                         "SELECT srs_id FROM gpkg_spatial_ref_sys WHERE "
                         "upper(organization) = upper('%q') AND "
                         "organization_coordsys_id = %d",
                         pszAuthorityName, nAuthorityCode );

        nSRSId = SQLGetInteger(hDB, pszSQL, &err);
        sqlite3_free(pszSQL);

        // Got a match? Return it!
        if ( OGRERR_NONE == err )
        {
            delete poSRS;
            return nSRSId;
        }

        // No match, but maybe we can use the nAuthorityCode as the nSRSId?
        pszSQL = sqlite3_mprintf(
                         "SELECT Count(*) FROM gpkg_spatial_ref_sys WHERE "
                         "srs_id = %d", nAuthorityCode );

        // Yep, we can!
        if ( SQLGetInteger(hDB, pszSQL, nullptr) == 0 )
            bCanUseAuthorityCode = true;
        sqlite3_free(pszSQL);
    }

    // Translate SRS to WKT.
    char *pszWKT1 = nullptr;
    char *pszWKT2 = nullptr;
    const char* const apszOptionsWkt1[] = { "FORMAT=WKT1_GDAL", nullptr };
    const char* const apszOptionsWkt2[] = { "FORMAT=WKT2_2015", nullptr };
    if( !(poSRS->IsGeographic() && poSRS->GetAxesCount() == 3) )
    {
        poSRS->exportToWkt( &pszWKT1, apszOptionsWkt1 );
        if( pszWKT1 && pszWKT1[0] == '\0' )
        {
            CPLFree(pszWKT1);
            pszWKT1 = nullptr;
        }
    }
    poSRS->exportToWkt( &pszWKT2, apszOptionsWkt2 );
    if( pszWKT2 && pszWKT2[0] == '\0' )
    {
        CPLFree(pszWKT2);
        pszWKT2 = nullptr;
    }

    if( !pszWKT1 && !pszWKT2 )
    {
        delete poSRS;
        CPLFree(pszWKT1);
        CPLFree(pszWKT2);
        return DEFAULT_SRID;
    }

    if( !m_bHasDefinition12_063 && pszWKT1 == nullptr && pszWKT2 != nullptr )
    {
        if( !ConvertGpkgSpatialRefSysToExtensionWkt2() )
        {
            delete poSRS;
            CPLFree(pszWKT1);
            CPLFree(pszWKT2);
            return DEFAULT_SRID;
        }
    }

    // Reuse the authority code number as SRS_ID if we can
    if ( bCanUseAuthorityCode )
    {
        nSRSId = nAuthorityCode;
    }
    // Otherwise, generate a new SRS_ID number (max + 1)
    else
    {
        // Get the current maximum srid in the srs table.
        const int nMaxSRSId
            = SQLGetInteger(
                hDB, "SELECT MAX(srs_id) FROM gpkg_spatial_ref_sys", nullptr );
        // At least 100000 to avoid conflicting with EPSG codes
        nSRSId = std::max(100000, nMaxSRSId + 1);
    }

    // Add new SRS row to gpkg_spatial_ref_sys.
    if( m_bHasDefinition12_063 )
    {
        if( pszAuthorityName != nullptr && nAuthorityCode > 0 )
        {
            pszSQL = sqlite3_mprintf(
                "INSERT INTO gpkg_spatial_ref_sys "
                "(srs_name,srs_id,organization,organization_coordsys_id,"
                "definition, definition_12_063) VALUES "
                "('%q', %d, upper('%q'), %d, '%q', '%q')",
                GetSrsName(*poSRS), nSRSId, pszAuthorityName, nAuthorityCode,
                pszWKT1 ? pszWKT1 : "undefined",
                pszWKT2 ? pszWKT2 : "undefined" );
        }
        else
        {
            pszSQL = sqlite3_mprintf(
                "INSERT INTO gpkg_spatial_ref_sys "
                "(srs_name,srs_id,organization,organization_coordsys_id,"
                "definition, definition_12_063) VALUES "
                "('%q', %d, upper('%q'), %d, '%q', '%q')",
                GetSrsName(*poSRS), nSRSId, "NONE", nSRSId,
                pszWKT1 ? pszWKT1 : "undefined",
                pszWKT2 ? pszWKT2 : "undefined" );
        }
    }
    else
    {
        if( pszAuthorityName != nullptr && nAuthorityCode > 0 )
        {
            pszSQL = sqlite3_mprintf(
                "INSERT INTO gpkg_spatial_ref_sys "
                "(srs_name,srs_id,organization,organization_coordsys_id,"
                "definition) VALUES ('%q', %d, upper('%q'), %d, '%q')",
                GetSrsName(*poSRS), nSRSId, pszAuthorityName, nAuthorityCode,
                pszWKT1 ? pszWKT1 : "undefined" );
        }
        else
        {
            pszSQL = sqlite3_mprintf(
                "INSERT INTO gpkg_spatial_ref_sys "
                "(srs_name,srs_id,organization,organization_coordsys_id,"
                "definition) VALUES ('%q', %d, upper('%q'), %d, '%q')",
                GetSrsName(*poSRS), nSRSId, "NONE", nSRSId,
                pszWKT1 ? pszWKT1 : "undefined" );
        }
    }

    // Add new row to gpkg_spatial_ref_sys.
    CPL_IGNORE_RET_VAL( SQLCommand(hDB, pszSQL) );

    // Free everything that was allocated.
    CPLFree(pszWKT1);
    CPLFree(pszWKT2);
    sqlite3_free(pszSQL);
    delete poSRS;

    return nSRSId;
}

/************************************************************************/
/*                        GDALGeoPackageDataset()                       */
/************************************************************************/

GDALGeoPackageDataset::GDALGeoPackageDataset() :
    m_nApplicationId(GPKG_APPLICATION_ID),
    m_nUserVersion(GPKG_1_2_VERSION),
    m_papoLayers(nullptr),
    m_nLayers(0),
#ifdef ENABLE_GPKG_OGR_CONTENTS
    m_bHasGPKGOGRContents(false),
#endif
    m_bHasGPKGGeometryColumns(false),
    m_bHasDefinition12_063(false),
    m_bIdentifierAsCO(false),
    m_bDescriptionAsCO(false),
    m_bHasReadMetadataFromStorage(false),
    m_bMetadataDirty(false),
    m_papszSubDatasets(nullptr),
    m_pszProjection(nullptr),
    m_bRecordInsertedInGPKGContent(false),
    m_bGeoTransformValid(false),
    m_nSRID(-1),  // Unknown cartesian.
    m_dfTMSMinX(0.0),
    m_dfTMSMaxY(0.0),
    m_nOverviewCount(0),
    m_papoOverviewDS(nullptr),
    m_bZoomOther(false),
    m_bInFlushCache(false),
    m_bTableCreated(false),
    m_osTilingScheme("CUSTOM"),
    m_bMapTableToExtensionsBuilt(false),
    m_bMapTableToContentsBuilt(false)
{
    m_adfGeoTransform[0] = 0.0;
    m_adfGeoTransform[1] = 1.0;
    m_adfGeoTransform[2] = 0.0;
    m_adfGeoTransform[3] = 0.0;
    m_adfGeoTransform[4] = 0.0;
    m_adfGeoTransform[5] = 1.0;
}

/************************************************************************/
/*                       ~GDALGeoPackageDataset()                       */
/************************************************************************/

GDALGeoPackageDataset::~GDALGeoPackageDataset()
{
    SetPamFlags(0);

    if( eAccess == GA_Update &&
        m_poParentDS == nullptr && !m_osRasterTable.empty() &&
        !m_bGeoTransformValid )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Raster table %s not correctly initialized due to missing "
                  "call to SetGeoTransform()",
                  m_osRasterTable.c_str());
    }

    GDALGeoPackageDataset::FlushCache();
    FlushMetadata();

    if( eAccess == GA_Update )
    {
        CreateOGREmptyTableIfNeeded();
    }

    // Destroy bands now since we don't want
    // GDALGPKGMBTilesLikeRasterBand::FlushCache() to run after dataset
    // destruction
    for( int i = 0; i < nBands; i++ )
        delete papoBands[i];
    nBands = 0;
    CPLFree(papoBands);
    papoBands = nullptr;

    // Destroy overviews before cleaning m_hTempDB as they could still
    // need it
    for( int i = 0; i < m_nOverviewCount; i++ )
        delete m_papoOverviewDS[i];

    if( m_poParentDS != nullptr )
    {
        hDB = nullptr;
    }

    for( int i = 0; i < m_nLayers; i++ )
        delete m_papoLayers[i];

    CPLFree( m_papoLayers );
    CPLFree( m_papoOverviewDS );
    CSLDestroy( m_papszSubDatasets );
    CPLFree(m_pszProjection);

    std::map<int, OGRSpatialReference*>::iterator oIter =
                                                    m_oMapSrsIdToSrs.begin();
    for( ; oIter != m_oMapSrsIdToSrs.end(); ++oIter )
    {
        OGRSpatialReference* poSRS = oIter->second;
        if( poSRS )
            poSRS->Release();
    }
}

/************************************************************************/
/*                         ICanIWriteBlock()                            */
/************************************************************************/

bool GDALGeoPackageDataset::ICanIWriteBlock()
{
    if( !bUpdate )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "IWriteBlock() not supported on dataset opened in read-only mode");
        return false;
    }

    if( m_pabyCachedTiles == nullptr )
    {
        return false;
    }

    if( !m_bGeoTransformValid || m_nSRID == UNKNOWN_SRID )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "IWriteBlock() not supported if georeferencing not set");
        return false;
    }
    return true;
}

/************************************************************************/
/*                      GetNameTypeMapFromSQliteMaster()                */
/************************************************************************/

const std::map<CPLString, CPLString> &
                        GDALGeoPackageDataset::GetNameTypeMapFromSQliteMaster()
{
    if( !m_oMapNameToType.empty() )
        return m_oMapNameToType;

    CPLString osSQL(
            "SELECT name, type FROM sqlite_master WHERE "
            "type IN ('view', 'table') OR "
            "(name LIKE 'trigger_%_feature_count_%' AND type = 'trigger')");
    const int nTableLimit =
                atoi(CPLGetConfigOption("OGR_TABLE_LIMIT", "10000"));
    if( nTableLimit > 0 )
    {
        osSQL += " LIMIT ";
        osSQL += CPLSPrintf("%d", 1 + 3 * nTableLimit);
    }

    SQLResult oResult;
    OGRErr err = SQLQuery(hDB, osSQL, &oResult);
    if( err == OGRERR_NONE )
    {
        for( int i = 0; i < oResult.nRowCount; i++ )
        {
            const char* pszName = SQLResultGetValue(&oResult, 0, i);
            const char* pszType = SQLResultGetValue(&oResult, 1, i);
            m_oMapNameToType[ CPLString(pszName).toupper() ] = pszType;
        }
    }
    SQLResultFree(&oResult);

    return m_oMapNameToType;
}

/************************************************************************/
/*                    RemoveTableFromSQLiteMasterCache()                */
/************************************************************************/

void GDALGeoPackageDataset::RemoveTableFromSQLiteMasterCache(
                                                    const char* pszTableName)
{
    m_oMapNameToType.erase(CPLString(pszTableName).toupper());
}

/************************************************************************/
/*                  GetUnknownExtensionsTableSpecific()                 */
/************************************************************************/

const std::map< CPLString, std::vector<GPKGExtensionDesc> > &
                    GDALGeoPackageDataset::GetUnknownExtensionsTableSpecific()
{
    if( m_bMapTableToExtensionsBuilt )
        return m_oMapTableToExtensions;
    m_bMapTableToExtensionsBuilt = true;

    if( !HasExtensionsTable() )
        return m_oMapTableToExtensions;

    CPLString osSQL("SELECT table_name, extension_name, definition, scope "
            "FROM gpkg_extensions WHERE "
            "table_name IS NOT NULL "
            "AND extension_name IS NOT NULL "
            "AND definition IS NOT NULL "
            "AND scope IS NOT NULL "
            "AND extension_name NOT IN ('gpkg_geom_CIRCULARSTRING', "
            "'gpkg_geom_COMPOUNDCURVE', 'gpkg_geom_CURVEPOLYGON', 'gpkg_geom_MULTICURVE', "
            "'gpkg_geom_MULTISURFACE', 'gpkg_geom_CURVE', 'gpkg_geom_SURFACE', "
            "'gpkg_geom_POLYHEDRALSURFACE', 'gpkg_geom_TIN', 'gpkg_geom_TRIANGLE', "
            "'gpkg_rtree_index', 'gpkg_geometry_type_trigger', 'gpkg_srs_id_trigger', "
            "'gpkg_crs_wkt', 'gpkg_schema')");
    const int nTableLimit =
                atoi(CPLGetConfigOption("OGR_TABLE_LIMIT", "10000"));
    if( nTableLimit > 0 )
    {
        osSQL += " LIMIT ";
        osSQL += CPLSPrintf("%d", 1 + 10 * nTableLimit);
    }

    SQLResult oResult;
    OGRErr err = SQLQuery(hDB, osSQL, &oResult);
    if( err == OGRERR_NONE )
    {
        for( int i = 0; i < oResult.nRowCount; i++ )
        {
            const char* pszTableName = SQLResultGetValue(&oResult, 0, i);
            const char* pszExtensionName = SQLResultGetValue(&oResult, 1, i);
            const char* pszDefinition = SQLResultGetValue(&oResult, 2, i);
            const char* pszScope = SQLResultGetValue(&oResult, 3, i);
            GPKGExtensionDesc oDesc;
            oDesc.osExtensionName = pszExtensionName;
            oDesc.osDefinition = pszDefinition;
            oDesc.osScope = pszScope;
            m_oMapTableToExtensions[ CPLString(pszTableName).toupper() ].push_back(oDesc);
        }
    }
    SQLResultFree(&oResult);

    return m_oMapTableToExtensions;
}

/************************************************************************/
/*                           GetContents()                              */
/************************************************************************/

const std::map< CPLString, GPKGContentsDesc > &
                        GDALGeoPackageDataset::GetContents()
{
    if( m_bMapTableToContentsBuilt )
        return m_oMapTableToContents;
    m_bMapTableToContentsBuilt = true;

    CPLString osSQL("SELECT table_name, data_type, identifier, "
            "description, min_x, min_y, max_x, max_y "
            "FROM gpkg_contents WHERE table_name IS NOT NULL");
    const int nTableLimit =
                atoi(CPLGetConfigOption("OGR_TABLE_LIMIT", "10000"));
    if( nTableLimit > 0 )
    {
        osSQL += " LIMIT ";
        osSQL += CPLSPrintf("%d", 1 + nTableLimit);
    }

    SQLResult oResult;
    OGRErr err = SQLQuery(hDB, osSQL, &oResult);
    if( err == OGRERR_NONE )
    {
        for( int i = 0; i < oResult.nRowCount; i++ )
        {
            const char* pszTableName = SQLResultGetValue(&oResult, 0, i);
            const char* pszDataType = SQLResultGetValue(&oResult, 1, i);
            const char* pszIdentifier = SQLResultGetValue(&oResult, 2, i);
            const char* pszDescription = SQLResultGetValue(&oResult, 3, i);
            const char* pszMinX = SQLResultGetValue(&oResult, 4, i);
            const char* pszMinY = SQLResultGetValue(&oResult, 5, i);
            const char* pszMaxX = SQLResultGetValue(&oResult, 6, i);
            const char* pszMaxY = SQLResultGetValue(&oResult, 7, i);
            GPKGContentsDesc oDesc;
            if( pszDataType ) oDesc.osDataType = pszDataType;
            if( pszIdentifier ) oDesc.osIdentifier = pszIdentifier;
            if( pszDescription ) oDesc.osDescription = pszDescription;
            if( pszMinX ) oDesc.osMinX = pszMinX;
            if( pszMinY ) oDesc.osMinY = pszMinY;
            if( pszMaxX ) oDesc.osMaxX = pszMaxX;
            if( pszMaxY ) oDesc.osMaxY = pszMaxY;
            m_oMapTableToContents[ CPLString(pszTableName).toupper()] = oDesc;
        }
    }
    SQLResultFree(&oResult);

    return m_oMapTableToContents;
}

/************************************************************************/
/*                                Open()                                */
/************************************************************************/

int GDALGeoPackageDataset::Open( GDALOpenInfo* poOpenInfo )
{
    CPLAssert( m_nLayers == 0 );
    CPLAssert( hDB == nullptr );

    SetDescription( poOpenInfo->pszFilename );
    CPLString osFilename( poOpenInfo->pszFilename );
    CPLString osSubdatasetTableName;
    GByte abyHeaderLetMeHerePlease[100];
    const GByte* pabyHeader = poOpenInfo->pabyHeader;
    if( STARTS_WITH_CI(poOpenInfo->pszFilename, "GPKG:") )
    {
        char** papszTokens = CSLTokenizeString2(poOpenInfo->pszFilename, ":", 0);
        int nCount = CSLCount(papszTokens);
        if( nCount != 3 && nCount != 4 )
        {
            CSLDestroy(papszTokens);
            return FALSE;
        }

        if( nCount == 3 )
        {
            osFilename = papszTokens[1];
        }
        /* GPKG:C:\BLA.GPKG:foo */
        else if ( nCount == 4 && strlen(papszTokens[1]) == 1 &&
                  (papszTokens[2][0] == '/' || papszTokens[2][0] == '\\') )
        {
            osFilename = CPLString(papszTokens[1]) + ":" + papszTokens[2];
        }
        osSubdatasetTableName = papszTokens[nCount-1];

        CSLDestroy(papszTokens);
        VSILFILE *fp = VSIFOpenL(osFilename, "rb");
        if( fp != nullptr )
        {
            VSIFReadL( abyHeaderLetMeHerePlease, 1, 100, fp );
            VSIFCloseL(fp);
        }
        pabyHeader = abyHeaderLetMeHerePlease;
    }
    else if( poOpenInfo->pabyHeader &&
            STARTS_WITH((const char*)poOpenInfo->pabyHeader, "SQLite format 3") )
    {
        m_bCallUndeclareFileNotToOpen = true;
        GDALOpenInfoDeclareFileNotToOpen(osFilename,
                                    poOpenInfo->pabyHeader,
                                    poOpenInfo->nHeaderBytes);
    }

    bUpdate = poOpenInfo->eAccess == GA_Update;
    eAccess = poOpenInfo->eAccess; /* hum annoying duplication */
    m_pszFilename = CPLStrdup( osFilename );

#ifdef ENABLE_SQL_GPKG_FORMAT
    if( poOpenInfo->pabyHeader &&
        STARTS_WITH((const char*)poOpenInfo->pabyHeader, "-- SQL GPKG") &&
        poOpenInfo->fpL != nullptr )
    {
        if( sqlite3_open_v2( ":memory:", &hDB, SQLITE_OPEN_READWRITE, nullptr )
                != SQLITE_OK )
        {
            return FALSE;
        }

        InstallSQLFunctions();

        // Ingest the lines of the dump
        VSIFSeekL( poOpenInfo->fpL, 0, SEEK_SET );
        const char* pszLine;
        while( (pszLine = CPLReadLineL( poOpenInfo->fpL )) != nullptr )
        {
            if( STARTS_WITH(pszLine, "--") )
                continue;

            // Blacklist a few words tat might have security implications
            // Basically we just want to allow CREATE TABLE and INSERT INTO
            if( CPLString(pszLine).ifind("ATTACH") != std::string::npos ||
                CPLString(pszLine).ifind("DETACH") != std::string::npos ||
                CPLString(pszLine).ifind("PRAGMA") != std::string::npos ||
                CPLString(pszLine).ifind("SELECT") != std::string::npos ||
                CPLString(pszLine).ifind("UPDATE") != std::string::npos ||
                CPLString(pszLine).ifind("REPLACE") != std::string::npos ||
                CPLString(pszLine).ifind("DELETE") != std::string::npos ||
                CPLString(pszLine).ifind("DROP") != std::string::npos ||
                CPLString(pszLine).ifind("ALTER") != std::string::npos||
                CPLString(pszLine).ifind("VIRTUAL") != std::string::npos )
            {
                bool bOK = false;
                // Accept creation of spatial index
                if( STARTS_WITH_CI(pszLine, "CREATE VIRTUAL TABLE ") )
                {
                    const char* pszStr = pszLine +
                                        strlen("CREATE VIRTUAL TABLE ");
                    if( *pszStr == '"' )
                        pszStr ++;
                    while( (*pszStr >= 'a' && *pszStr <= 'z') ||
                            (*pszStr >= 'A' && *pszStr <= 'Z') ||
                            *pszStr == '_' )
                    {
                        pszStr ++;
                    }
                    if( *pszStr == '"' )
                        pszStr ++;
                    if( EQUAL(pszStr,
                        " USING rtree(id, minx, maxx, miny, maxy);") )
                    {
                        bOK = true;
                    }
                }
                // Accept INSERT INTO rtree_poly_geom SELECT fid, ST_MinX(geom), ST_MaxX(geom), ST_MinY(geom), ST_MaxY(geom) FROM poly;
                else if( STARTS_WITH_CI(pszLine, "INSERT INTO rtree_") &&
                    CPLString(pszLine).ifind("SELECT") != std::string::npos )
                {
                    char** papszTokens = CSLTokenizeString2( pszLine, " (),,", 0 );
                    if( CSLCount(papszTokens) == 15 &&
                        EQUAL(papszTokens[3], "SELECT") &&
                        EQUAL(papszTokens[5], "ST_MinX") &&
                        EQUAL(papszTokens[7], "ST_MaxX") &&
                        EQUAL(papszTokens[9], "ST_MinY") &&
                        EQUAL(papszTokens[11], "ST_MaxY") &&
                        EQUAL(papszTokens[13], "FROM") )
                    {
                        bOK = TRUE;
                    }
                    CSLDestroy(papszTokens);
                }

                if( !bOK )
                {
                    CPLError(CE_Failure, CPLE_NotSupported,
                            "Rejected statement: %s", pszLine);
                    return FALSE;
                }
            }
            char* pszErrMsg = nullptr;
            if( sqlite3_exec( hDB, pszLine, nullptr, nullptr, &pszErrMsg ) != SQLITE_OK )
            {
                if( pszErrMsg )
                    CPLDebug("SQLITE", "Error %s", pszErrMsg);
            }
            sqlite3_free(pszErrMsg);
        }
    }

    else if( pabyHeader != nullptr )
#endif
    {
        if (poOpenInfo->fpL )
        {
            // See above comment about -wal locking for the importance of
            // closing that file, prior to calling sqlite3_open()
            VSIFCloseL(poOpenInfo->fpL);
            poOpenInfo->fpL = nullptr;
        }

        /* See if we can open the SQLite database */
        if( !OpenOrCreateDB(bUpdate
                        ? SQLITE_OPEN_READWRITE
                        : SQLITE_OPEN_READONLY) )
            return FALSE;


        memcpy(&m_nApplicationId, pabyHeader + knApplicationIdPos, 4);
        m_nApplicationId = CPL_MSBWORD32(m_nApplicationId);
        memcpy(&m_nUserVersion, pabyHeader + knUserVersionPos, 4);
        m_nUserVersion = CPL_MSBWORD32(m_nUserVersion);
        if( m_nApplicationId == GP10_APPLICATION_ID )
        {
            CPLDebug("GPKG", "GeoPackage v1.0");
        }
        else if( m_nApplicationId == GP11_APPLICATION_ID )
        {
            CPLDebug("GPKG", "GeoPackage v1.1");
        }
        else if( m_nApplicationId == GPKG_APPLICATION_ID &&
                m_nUserVersion >= GPKG_1_2_VERSION )
        {
            CPLDebug("GPKG", "GeoPackage v%d.%d.%d",
                    m_nUserVersion / 10000,
                    (m_nUserVersion % 10000) / 100,
                    m_nUserVersion % 100);
        }
    }

    /* Requirement 6: The SQLite PRAGMA integrity_check SQL command SHALL return “ok” */
    /* http://opengis.github.io/geopackage/#_file_integrity */
    /* Disable integrity check by default, since it is expensive on big files */
    if( CPLTestBool(CPLGetConfigOption("OGR_GPKG_INTEGRITY_CHECK", "NO")) &&
        OGRERR_NONE != PragmaCheck("integrity_check", "ok", 1) )
    {
        CPLError( CE_Failure, CPLE_AppDefined, "pragma integrity_check on '%s' failed",
                  m_pszFilename);
        return FALSE;
    }

    /* Requirement 7: The SQLite PRAGMA foreign_key_check() SQL with no */
    /* parameter value SHALL return an empty result set */
    /* http://opengis.github.io/geopackage/#_file_integrity */
    if ( CPLTestBool(CPLGetConfigOption("OGR_GPKG_FOREIGN_KEY_CHECK", "YES")) &&
         OGRERR_NONE != PragmaCheck("foreign_key_check", "", 0) )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "pragma foreign_key_check on '%s' failed. You can disable "
                  "this check by setting the OGR_GPKG_FOREIGN_KEY_CHECK "
                  "configuration option to NO",
                  m_pszFilename);
        return FALSE;
    }

    /* Check for requirement metadata tables */
    /* Requirement 10: gpkg_spatial_ref_sys must exist */
    /* Requirement 13: gpkg_contents must exist */
    if( SQLGetInteger(hDB,
        "SELECT COUNT(*) FROM sqlite_master WHERE "
        "name IN ('gpkg_spatial_ref_sys', 'gpkg_contents') AND "
        "type IN ('table', 'view')", nullptr) != 2 )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "At least one of the required GeoPackage tables, "
                  "gpkg_spatial_ref_sys or gpkg_contents, is missing");
        return FALSE;
    }

    // Detect definition_12_063 column
    {
        sqlite3_stmt* hSQLStmt = nullptr;
        int rc = sqlite3_prepare_v2( hDB,
            "SELECT definition_12_063 FROM gpkg_spatial_ref_sys ", -1,
            &hSQLStmt, nullptr );
        if( rc == SQLITE_OK )
        {
            m_bHasDefinition12_063 = true;
            sqlite3_finalize(hSQLStmt);
        }
    }

#ifdef ENABLE_GPKG_OGR_CONTENTS
    if( SQLGetInteger(hDB,
            "SELECT 1 FROM sqlite_master WHERE "
            "name = 'gpkg_ogr_contents' AND type = 'table'", nullptr) == 1 )
    {
        m_bHasGPKGOGRContents = true;
    }
#endif

    CheckUnknownExtensions();

    int bRet = FALSE;
    if( poOpenInfo->nOpenFlags & GDAL_OF_VECTOR )
    {
        m_bHasGPKGGeometryColumns = SQLGetInteger(hDB,
            "SELECT 1 FROM sqlite_master WHERE "
            "name = 'gpkg_geometry_columns' AND "
            "type IN ('table', 'view')", nullptr) == 1;
    }
    if( m_bHasGPKGGeometryColumns )
    {
        /* Load layer definitions for all tables in gpkg_contents & gpkg_geometry_columns */
        /* and non-spatial tables as well */
        std::string osSQL =
            "SELECT c.table_name, c.identifier, 1 as is_spatial, g.column_name, g.geometry_type_name, g.z, g.m, c.min_x, c.min_y, c.max_x, c.max_y, 1 AS is_in_gpkg_contents "
            "  FROM gpkg_geometry_columns g JOIN gpkg_contents c ON (g.table_name = c.table_name)"
            "  WHERE c.table_name IS NOT NULL AND"
            "  c.table_name <> 'ogr_empty_table' AND"
            "  c.data_type = 'features' "
            // aspatial: Was the only method available in OGR 2.0 and 2.1
            // attributes: GPKG 1.2 or later
            "UNION ALL "
            "SELECT table_name, identifier, 0 as is_spatial, NULL, NULL, 0, 0, 0 AS xmin, 0 AS ymin, 0 AS xmax, 0 AS ymax, 1 AS is_in_gpkg_contents "
            "  FROM gpkg_contents"
            "  WHERE table_name IS NOT NULL AND data_type IN ('aspatial', 'attributes') ";

        const char* pszListAllTables = CSLFetchNameValueDef(poOpenInfo->papszOpenOptions, "LIST_ALL_TABLES", "AUTO");
        bool bHasASpatialOrAttributes = HasGDALAspatialExtension();
        if( !bHasASpatialOrAttributes )
        {
            SQLResult oResultTable;
            OGRErr err = SQLQuery(hDB,
                "SELECT * FROM gpkg_contents WHERE "
                "data_type = 'attributes' LIMIT 1",
                &oResultTable);
            bHasASpatialOrAttributes = ( err == OGRERR_NONE &&
                                         oResultTable.nRowCount == 1 );
            SQLResultFree(&oResultTable);
        }
        if( EQUAL(pszListAllTables, "YES") ||
            (!bHasASpatialOrAttributes && EQUAL(pszListAllTables, "AUTO")) )
        {
            // vgpkg_ is Spatialite virtual table
            osSQL += "UNION ALL "
                    "SELECT name, name, 0 as is_spatial, NULL, NULL, 0, 0, 0 AS xmin, 0 AS ymin, 0 AS xmax, 0 AS ymax, 0 AS is_in_gpkg_contents "
                    "FROM sqlite_master WHERE type IN ('table', 'view') "
                    "AND name IS NOT NULL AND name NOT LIKE 'gpkg_%' "
                    "AND name NOT LIKE 'vgpkg_%' "
                    "AND name NOT LIKE 'rtree_%' AND name NOT LIKE 'sqlite_%' "
                    // Avoid reading those views from simple_sewer_features.gpkg
                    "AND name NOT IN ('st_spatial_ref_sys', 'spatial_ref_sys', 'st_geometry_columns') "
                    "AND lower(name) NOT IN (SELECT lower(table_name) FROM gpkg_contents)";
        }
        const int nTableLimit =
                    atoi(CPLGetConfigOption("OGR_TABLE_LIMIT", "10000"));
        if( nTableLimit > 0 )
        {
            osSQL += " LIMIT ";
            osSQL += CPLSPrintf("%d", 1 + nTableLimit);
        }

        SQLResult oResult;
        OGRErr err = SQLQuery(hDB, osSQL.c_str(), &oResult);
        if  ( err != OGRERR_NONE )
        {
            SQLResultFree(&oResult);
            return FALSE;
        }

        if( nTableLimit > 0 && oResult.nRowCount > nTableLimit )
        {
            CPLError(CE_Warning, CPLE_AppDefined,
                     "File has more than %d vector tables. "
                     "Limiting to first %d (can be overridden with "
                     "OGR_TABLE_LIMIT config option)",
                     nTableLimit, nTableLimit);
            oResult.nRowCount = nTableLimit;
        }

        if ( oResult.nRowCount > 0 )
        {
            bRet = TRUE;

            m_papoLayers = (OGRGeoPackageTableLayer**)CPLMalloc(sizeof(OGRGeoPackageTableLayer*) * oResult.nRowCount);

            std::set<CPLString> oSetTables;
            for ( int i = 0; i < oResult.nRowCount; i++ )
            {
                const char *pszTableName = SQLResultGetValue(&oResult, 0, i);
                if( oSetTables.find(pszTableName) != oSetTables.end() )
                {
                    // This should normally not happen if all constraints are properly set
                    CPLError(CE_Warning, CPLE_AppDefined,
                             "Table %s appearing several times in "
                             "gpkg_contents and/or gpkg_geometry_columns",
                             pszTableName);
                    continue;
                }
                oSetTables.insert(pszTableName);
                bool bIsSpatial = CPL_TO_BOOL(SQLResultGetValueAsInteger(&oResult, 2, i));
                const char* pszGeomColName = SQLResultGetValue(&oResult, 3, i);
                const char* pszGeomType = SQLResultGetValue(&oResult, 4, i);
                const char* pszZ = SQLResultGetValue(&oResult, 5, i);
                const char* pszM = SQLResultGetValue(&oResult, 6, i);
                bool bIsInGpkgContents = CPL_TO_BOOL(SQLResultGetValueAsInteger(&oResult, 11, i));
                OGRGeoPackageTableLayer *poLayer = new OGRGeoPackageTableLayer(this, pszTableName);
                poLayer->SetOpeningParameters(bIsInGpkgContents,
                                              bIsSpatial,
                                              pszGeomColName,
                                              pszGeomType,
                                              pszZ && atoi(pszZ) > 0,
                                              pszM && atoi(pszM) > 0);
                m_papoLayers[m_nLayers++] = poLayer;
            }
        }

        SQLResultFree(&oResult);
    }

    bool bHasTileMatrixSet = false;
    if( poOpenInfo->nOpenFlags & GDAL_OF_RASTER )
    {
        bHasTileMatrixSet = SQLGetInteger(hDB,
            "SELECT 1 FROM sqlite_master WHERE "
            "name = 'gpkg_tile_matrix_set' AND "
            "type IN ('table', 'view')", nullptr) == 1;
    }
    if( bHasTileMatrixSet )
    {
        SQLResult oResult;
        std::string osSQL =
            "SELECT c.table_name, c.identifier, c.description, c.srs_id, "
            "c.min_x, c.min_y, c.max_x, c.max_y, "
            "tms.min_x, tms.min_y, tms.max_x, tms.max_y, c.data_type "
            "FROM gpkg_contents c JOIN gpkg_tile_matrix_set tms ON "
            "c.table_name = tms.table_name WHERE "
            "c.table_name IS NOT NULL AND "
            "tms.min_x IS NOT NULL AND "
            "tms.min_y IS NOT NULL AND "
            "tms.max_x IS NOT NULL AND "
            "tms.max_y IS NOT NULL AND "
            "data_type IN ('tiles', '2d-gridded-coverage')";
        if( CSLFetchNameValue( poOpenInfo->papszOpenOptions, "TABLE") )
            osSubdatasetTableName = CSLFetchNameValue( poOpenInfo->papszOpenOptions, "TABLE");
        if( !osSubdatasetTableName.empty() )
        {
            char* pszTmp = sqlite3_mprintf(" AND c.table_name='%q'", osSubdatasetTableName.c_str());
            osSQL += pszTmp;
            sqlite3_free(pszTmp);
            SetPhysicalFilename( osFilename.c_str() );
        }
        osSQL += " LIMIT 1000";

        const OGRErr err = SQLQuery(hDB, osSQL.c_str(), &oResult);
        if  ( err != OGRERR_NONE )
        {
            SQLResultFree(&oResult);
            return FALSE;
        }

        if( oResult.nRowCount == 0 && !osSubdatasetTableName.empty() )
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Cannot find table '%s' in GeoPackage dataset",
                     osSubdatasetTableName.c_str());
        }
        else if( oResult.nRowCount == 1 )
        {
            const char *pszTableName = SQLResultGetValue(&oResult, 0, 0);
            const char* pszIdentifier = SQLResultGetValue(&oResult, 1, 0);
            const char* pszDescription = SQLResultGetValue(&oResult, 2, 0);
            const char* pszSRSId = SQLResultGetValue(&oResult, 3, 0);
            const char* pszMinX = SQLResultGetValue(&oResult, 4, 0);
            const char* pszMinY = SQLResultGetValue(&oResult, 5, 0);
            const char* pszMaxX = SQLResultGetValue(&oResult, 6, 0);
            const char* pszMaxY = SQLResultGetValue(&oResult, 7, 0);
            const char* pszTMSMinX = SQLResultGetValue(&oResult, 8, 0);
            const char* pszTMSMinY = SQLResultGetValue(&oResult, 9, 0);
            const char* pszTMSMaxX = SQLResultGetValue(&oResult, 10, 0);
            const char* pszTMSMaxY = SQLResultGetValue(&oResult, 11, 0);
            const char* pszDataType = SQLResultGetValue(&oResult, 12, 0);

            bRet = OpenRaster( pszTableName, pszIdentifier, pszDescription,
                                pszSRSId ? atoi(pszSRSId) : 0,
                                CPLAtof(pszTMSMinX), CPLAtof(pszTMSMinY),
                                CPLAtof(pszTMSMaxX), CPLAtof(pszTMSMaxY),
                                pszMinX, pszMinY, pszMaxX, pszMaxY,
                                EQUAL(pszDataType, "tiles"),
                                poOpenInfo->papszOpenOptions );
        }
        else if( oResult.nRowCount >= 1 )
        {
            bRet = TRUE;

            if( oResult.nRowCount == 1000 )
            {
                CPLError(CE_Warning, CPLE_AppDefined,
                         "File has more than 1000 raster tables. "
                         "Limiting to first 1000");
            }

            int nSDSCount = 0;
            for ( int i = 0; i < oResult.nRowCount; i++ )
            {
                const char *pszTableName = SQLResultGetValue(&oResult, 0, i);
                const char *pszIdentifier = SQLResultGetValue(&oResult, 1, i);

                m_papszSubDatasets = CSLSetNameValue( m_papszSubDatasets,
                                                    CPLSPrintf("SUBDATASET_%d_NAME", nSDSCount+1),
                                                    CPLSPrintf("GPKG:%s:%s", m_pszFilename, pszTableName) );
                if( pszIdentifier )
                    m_papszSubDatasets = CSLSetNameValue( m_papszSubDatasets,
                                                            CPLSPrintf("SUBDATASET_%d_DESC", nSDSCount+1),
                                                            CPLSPrintf("%s - %s", pszTableName, pszIdentifier) );
                else
                    m_papszSubDatasets = CSLSetNameValue( m_papszSubDatasets,
                                                            CPLSPrintf("SUBDATASET_%d_DESC", nSDSCount+1),
                                                            pszTableName );

                nSDSCount ++;
            }
        }

        SQLResultFree(&oResult);
    }

    if( !bRet && (poOpenInfo->nOpenFlags & GDAL_OF_VECTOR) )
    {
        if ( (poOpenInfo->nOpenFlags & GDAL_OF_UPDATE) )
        {
            bRet = TRUE;
        }
        else
        {
            CPLDebug("GPKG",
                     "This GeoPackage has no vector content and is opened "
                     "in read-only mode. If you open it in update mode, "
                     "opening will be successful.");
        }
    }

    return bRet;
}

/************************************************************************/
/*                         InitRaster()                                 */
/************************************************************************/

bool GDALGeoPackageDataset::InitRaster( GDALGeoPackageDataset* poParentDS,
                                        const char* pszTableName,
                                        double dfMinX,
                                        double dfMinY,
                                        double dfMaxX,
                                        double dfMaxY,
                                        const char* pszContentsMinX,
                                        const char* pszContentsMinY,
                                        const char* pszContentsMaxX,
                                        const char* pszContentsMaxY,
                                        char** papszOpenOptionsIn,
                                        const SQLResult& oResult,
                                        int nIdxInResult )
{
    m_osRasterTable = pszTableName;
    m_dfTMSMinX = dfMinX;
    m_dfTMSMaxY = dfMaxY;

    // Despite prior checking, the type might be Binary and
    // SQLResultGetValue() not working properly on it
    int nZoomLevel = atoi(SQLResultGetValue(&oResult, 0, nIdxInResult));
    if( nZoomLevel < 0 || nZoomLevel > 65536 )
    {
        return false;
    }
    double dfPixelXSize = CPLAtof(SQLResultGetValue(&oResult, 1, nIdxInResult));
    double dfPixelYSize = CPLAtof(SQLResultGetValue(&oResult, 2, nIdxInResult));
    if( dfPixelXSize <= 0 || dfPixelYSize <= 0 )
    {
        return false;
    }
    int nTileWidth = atoi(SQLResultGetValue(&oResult, 3, nIdxInResult));
    int nTileHeight = atoi(SQLResultGetValue(&oResult, 4, nIdxInResult));
    if( nTileWidth <= 0 || nTileWidth > 65536 ||
        nTileHeight <= 0 || nTileHeight > 65536 )
    {
        return false;
    }
    int nTileMatrixWidth = static_cast<int>(
        std::min(static_cast<GIntBig>(INT_MAX),
                 CPLAtoGIntBig(SQLResultGetValue(&oResult, 5, nIdxInResult))));
    int nTileMatrixHeight = static_cast<int>(
        std::min(static_cast<GIntBig>(INT_MAX),
                 CPLAtoGIntBig(SQLResultGetValue(&oResult, 6, nIdxInResult))));
    if( nTileMatrixWidth <= 0 || nTileMatrixHeight <= 0 )
    {
        return false;
    }

    /* Use content bounds in priority over tile_matrix_set bounds */
    double dfGDALMinX = dfMinX;
    double dfGDALMinY = dfMinY;
    double dfGDALMaxX = dfMaxX;
    double dfGDALMaxY = dfMaxY;
    pszContentsMinX = CSLFetchNameValueDef(papszOpenOptionsIn, "MINX", pszContentsMinX);
    pszContentsMinY = CSLFetchNameValueDef(papszOpenOptionsIn, "MINY", pszContentsMinY);
    pszContentsMaxX = CSLFetchNameValueDef(papszOpenOptionsIn, "MAXX", pszContentsMaxX);
    pszContentsMaxY = CSLFetchNameValueDef(papszOpenOptionsIn, "MAXY", pszContentsMaxY);
    if( pszContentsMinX != nullptr && pszContentsMinY != nullptr &&
        pszContentsMaxX != nullptr && pszContentsMaxY != nullptr )
    {
        if( CPLAtof(pszContentsMinX) < CPLAtof(pszContentsMaxX) &&
            CPLAtof(pszContentsMinY) < CPLAtof(pszContentsMaxY) )
        {
            dfGDALMinX = CPLAtof(pszContentsMinX);
            dfGDALMinY = CPLAtof(pszContentsMinY);
            dfGDALMaxX = CPLAtof(pszContentsMaxX);
            dfGDALMaxY = CPLAtof(pszContentsMaxY);
        }
        else
        {
            CPLError(CE_Warning, CPLE_AppDefined,
                     "Illegal min_x/min_y/max_x/max_y values for %s in open "
                     "options and/or gpkg_contents. Using bounds of "
                     "gpkg_tile_matrix_set instead",
                     pszTableName);
        }
    }
    if( dfGDALMinX >= dfGDALMaxX || dfGDALMinY >= dfGDALMaxY )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Illegal min_x/min_y/max_x/max_y values for %s",
                 pszTableName);
        return false;
    }

    int nBandCount = atoi(CSLFetchNameValueDef(papszOpenOptionsIn, "BAND_COUNT", "4"));
    if( nBandCount != 1 && nBandCount != 2 && nBandCount != 3 && nBandCount != 4 )
        nBandCount = 4;
    if( (poParentDS ? poParentDS->m_eDT : m_eDT) != GDT_Byte )
        nBandCount = 1;

    return InitRaster(poParentDS, pszTableName, nZoomLevel, nBandCount, dfMinX, dfMaxY,
                      dfPixelXSize, dfPixelYSize, nTileWidth, nTileHeight,
                      nTileMatrixWidth, nTileMatrixHeight,
                      dfGDALMinX, dfGDALMinY, dfGDALMaxX, dfGDALMaxY );
}

/************************************************************************/
/*                      ComputeTileAndPixelShifts()                     */
/************************************************************************/

bool GDALGeoPackageDataset::ComputeTileAndPixelShifts()
{
    int nTileWidth, nTileHeight;
    GetRasterBand(1)->GetBlockSize(&nTileWidth, &nTileHeight);

    // Compute shift between GDAL origin and TileMatrixSet origin
    double dfShiftXPixels = (m_adfGeoTransform[0] - m_dfTMSMinX) / 
                                                        m_adfGeoTransform[1];
    if( dfShiftXPixels < INT_MIN || dfShiftXPixels + 0.5 > INT_MAX )
        return false;
    int nShiftXPixels = static_cast<int>(floor(0.5 + dfShiftXPixels));
    m_nShiftXTiles = static_cast<int>(floor(1.0 * nShiftXPixels / nTileWidth));
    m_nShiftXPixelsMod = ((nShiftXPixels % nTileWidth) + nTileWidth) % nTileWidth;
    double dfShiftYPixels = (m_adfGeoTransform[3] - m_dfTMSMaxY) /
                                                        m_adfGeoTransform[5];
    if( dfShiftYPixels < INT_MIN || dfShiftYPixels + 0.5 > INT_MAX )
        return false;
    int nShiftYPixels = static_cast<int>(floor(0.5 + dfShiftYPixels));
    m_nShiftYTiles = static_cast<int>(floor(1.0 * nShiftYPixels / nTileHeight));
    m_nShiftYPixelsMod = ((nShiftYPixels % nTileHeight) + nTileHeight) % nTileHeight;
    return true;
}

/************************************************************************/
/*                            AllocCachedTiles()                        */
/************************************************************************/

bool GDALGeoPackageDataset::AllocCachedTiles()
{
    int nTileWidth, nTileHeight;
    GetRasterBand(1)->GetBlockSize(&nTileWidth, &nTileHeight);

    const int nCacheCount =
        (m_nShiftXPixelsMod != 0 || m_nShiftYPixelsMod != 0) ? 4 :
        (bUpdate && m_eDT == GDT_Byte) ? 2 : 1;

    m_pabyCachedTiles = (GByte*) VSI_MALLOC3_VERBOSE(
        nCacheCount * (m_eDT == GDT_Byte ? 4 : 1) * m_nDTSize,
        nTileWidth, nTileHeight);
    if( m_pabyCachedTiles == nullptr )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Too big tiles: %d x %d", nTileWidth, nTileHeight);
        return false;
    }

    return true;
}

/************************************************************************/
/*                         InitRaster()                                 */
/************************************************************************/

bool GDALGeoPackageDataset::InitRaster( GDALGeoPackageDataset* poParentDS,
                                        const char* pszTableName,
                                        int nZoomLevel,
                                        int nBandCount,
                                        double dfTMSMinX,
                                        double dfTMSMaxY,
                                        double dfPixelXSize,
                                        double dfPixelYSize,
                                        int nTileWidth,
                                        int nTileHeight,
                                        int nTileMatrixWidth,
                                        int nTileMatrixHeight,
                                        double dfGDALMinX,
                                        double dfGDALMinY,
                                        double dfGDALMaxX,
                                        double dfGDALMaxY )
{
    m_osRasterTable = pszTableName;
    m_dfTMSMinX = dfTMSMinX;
    m_dfTMSMaxY = dfTMSMaxY;
    m_nZoomLevel = nZoomLevel;
    m_nTileMatrixWidth = nTileMatrixWidth;
    m_nTileMatrixHeight = nTileMatrixHeight;

    m_bGeoTransformValid = true;
    m_adfGeoTransform[0] = dfGDALMinX;
    m_adfGeoTransform[1] = dfPixelXSize;
    m_adfGeoTransform[3] = dfGDALMaxY;
    m_adfGeoTransform[5] = -dfPixelYSize;
    double dfRasterXSize = 0.5 + (dfGDALMaxX - dfGDALMinX) / dfPixelXSize;
    double dfRasterYSize = 0.5 + (dfGDALMaxY - dfGDALMinY) / dfPixelYSize;
    if( dfRasterXSize > INT_MAX || dfRasterYSize > INT_MAX )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Too big raster: %f x %f",
                 dfRasterXSize, dfRasterYSize);
        return false;
    }
    nRasterXSize = std::max(1, static_cast<int>(dfRasterXSize));
    nRasterYSize = std::max(1, static_cast<int>(dfRasterYSize));

    if( poParentDS )
    {
        m_poParentDS = poParentDS;
        bUpdate = poParentDS->bUpdate;
        eAccess = poParentDS->eAccess;
        hDB = poParentDS->hDB;
        m_eTF = poParentDS->m_eTF;
        m_eDT = poParentDS->m_eDT;
        m_nDTSize = poParentDS->m_nDTSize;
        m_dfScale = poParentDS->m_dfScale;
        m_dfOffset = poParentDS->m_dfOffset;
        m_dfPrecision = poParentDS->m_dfPrecision;
        m_usGPKGNull = poParentDS->m_usGPKGNull;
        m_nQuality = poParentDS->m_nQuality;
        m_nZLevel = poParentDS->m_nZLevel;
        m_bDither = poParentDS->m_bDither;
        /*m_nSRID = poParentDS->m_nSRID;*/
        m_osWHERE = poParentDS->m_osWHERE;
        SetDescription(CPLSPrintf("%s - zoom_level=%d",
                                  poParentDS->GetDescription(), m_nZoomLevel));
    }

    for(int i = 1; i <= nBandCount; i ++)
    {
        GDALGeoPackageRasterBand* poNewBand =
            new GDALGeoPackageRasterBand(this, nTileWidth, nTileHeight);
        if( poParentDS )
        {
            int bHasNoData = FALSE;
            double dfNoDataValue =
                poParentDS->GetRasterBand(1)->GetNoDataValue(&bHasNoData);
            if( bHasNoData )
                poNewBand->SetNoDataValueInternal(dfNoDataValue);
        }
        SetBand( i, poNewBand );
    }

    if( !ComputeTileAndPixelShifts() )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Overflow occurred in ComputeTileAndPixelShifts()");
        return false;
    }

    GDALPamDataset::SetMetadataItem("INTERLEAVE", "PIXEL", "IMAGE_STRUCTURE");
    GDALPamDataset::SetMetadataItem("ZOOM_LEVEL", CPLSPrintf("%d", m_nZoomLevel));

    return AllocCachedTiles();
}

/************************************************************************/
/*                 GDALGPKGMBTilesGetTileFormat()                       */
/************************************************************************/

GPKGTileFormat GDALGPKGMBTilesGetTileFormat(const char* pszTF )
{
    GPKGTileFormat eTF = GPKG_TF_PNG_JPEG;
    if( pszTF )
    {
        if( EQUAL(pszTF, "PNG_JPEG") || EQUAL(pszTF, "AUTO") )
            eTF = GPKG_TF_PNG_JPEG;
        else if( EQUAL(pszTF, "PNG") )
            eTF = GPKG_TF_PNG;
        else if( EQUAL(pszTF, "PNG8") )
            eTF = GPKG_TF_PNG8;
        else if( EQUAL(pszTF, "JPEG") )
            eTF = GPKG_TF_JPEG;
        else if( EQUAL(pszTF, "WEBP") )
            eTF = GPKG_TF_WEBP;
        else
        {
            CPLError(CE_Failure, CPLE_NotSupported,
                     "Unsuppoted value for TILE_FORMAT: %s", pszTF);
        }
    }
    return eTF;
}

/************************************************************************/
/*                         OpenRaster()                                 */
/************************************************************************/

bool GDALGeoPackageDataset::OpenRaster( const char* pszTableName,
                                        const char* pszIdentifier,
                                        const char* pszDescription,
                                        int nSRSId,
                                        double dfMinX,
                                        double dfMinY,
                                        double dfMaxX,
                                        double dfMaxY,
                                        const char* pszContentsMinX,
                                        const char* pszContentsMinY,
                                        const char* pszContentsMaxX,
                                        const char* pszContentsMaxY,
                                        bool bIsTiles,
                                        char** papszOpenOptionsIn )
{
    OGRErr err;
    SQLResult oResult;

    if( dfMinX >= dfMaxX || dfMinY >= dfMaxY )
        return false;

    // Config option just for debug, and for example force set to NaN
    // which is not supported
    CPLString osDataNull = CPLGetConfigOption("GPKG_NODATA", "");
    CPLString osUom;
    CPLString osFieldName;
    CPLString osGridCellEncoding;
    if( !bIsTiles )
    {
        char* pszSQL = sqlite3_mprintf(
            "SELECT datatype, scale, offset, data_null, precision FROM "
            "gpkg_2d_gridded_coverage_ancillary "
            "WHERE tile_matrix_set_name = '%q' "
            "AND datatype IN ('integer', 'float')"
            "AND (scale > 0 OR scale IS NULL)", pszTableName);
        err = SQLQuery(hDB, pszSQL, &oResult);
        sqlite3_free(pszSQL);
        if( err != OGRERR_NONE || oResult.nRowCount == 0 )
        {

            SQLResultFree(&oResult);
            return false;
        }
        const char* pszDataType = SQLResultGetValue(&oResult, 0, 0);
        const char* pszScale = SQLResultGetValue(&oResult, 1, 0);
        const char* pszOffset = SQLResultGetValue(&oResult, 2, 0);
        const char* pszDataNull = SQLResultGetValue(&oResult, 3, 0);
        const char* pszPrecision = SQLResultGetValue(&oResult, 4, 0);
        if( pszDataNull )
            osDataNull = pszDataNull;
        if( EQUAL(pszDataType, "float") )
        {
            SetDataType(GDT_Float32);
            m_eTF = GPKG_TF_TIFF_32BIT_FLOAT;
        }
        else
        {
            SetDataType(GDT_Float32);
            m_eTF = GPKG_TF_PNG_16BIT;
            const double dfScale = pszScale ? CPLAtof(pszScale) : 1.0;
            const double dfOffset = pszOffset ? CPLAtof(pszOffset) : 0.0;
            if( dfScale == 1.0 )
            {
                if( dfOffset == 0.0 )
                {
                    SetDataType(GDT_UInt16);
                }
                else if( dfOffset == -32768.0 )
                {
                    SetDataType(GDT_Int16);
                }
                else if( dfOffset == -32767.0 && !osDataNull.empty() &&
                         CPLAtof(osDataNull) == 65535.0 )
                    // Given that we will map the nodata value to -32768
                {
                    SetDataType(GDT_Int16);
                }
            }

            // Check that the tile offset and scales are compatible of a
            // final integer result.
            if( m_eDT != GDT_Float32 )
            {
                if( dfScale == 1.0 && dfOffset == -32768.0 &&
                    !osDataNull.empty() &&
                    CPLAtof(osDataNull) == 65535.0 )
                {
                    // Given that we will map the nodata value to -32768
                    pszSQL = sqlite3_mprintf(
                        "SELECT 1 FROM "
                        "gpkg_2d_gridded_tile_ancillary WHERE "
                        "tpudt_name = '%q' "
                        "AND NOT ((offset = 0.0 or offset = 1.0) "
                        "AND scale = 1.0) "
                        "LIMIT 1",
                        pszTableName);
                }
                else
                {
                    pszSQL = sqlite3_mprintf(
                        "SELECT 1 FROM "
                        "gpkg_2d_gridded_tile_ancillary WHERE "
                        "tpudt_name = '%q' "
                        "AND NOT (offset = 0.0 AND scale = 1.0) LIMIT 1",
                        pszTableName);
                }
                sqlite3_stmt* hSQLStmt = nullptr;
                int rc = sqlite3_prepare_v2( hDB, pszSQL, -1,
                                          &hSQLStmt, nullptr );

                if( rc == SQLITE_OK )
                {
                    if( sqlite3_step(hSQLStmt) == SQLITE_ROW )
                    {
                        SetDataType(GDT_Float32);
                    }
                    sqlite3_finalize( hSQLStmt );
                }
                else
                {
                    CPLError(CE_Failure, CPLE_AppDefined,
                             "Error when running %s", pszSQL);
                }
                sqlite3_free(pszSQL);
            }

            SetGlobalOffsetScale(dfOffset, dfScale);
        }
        if( pszPrecision )
            m_dfPrecision = CPLAtof(pszPrecision);
        SQLResultFree(&oResult);

        // Request those columns in a separate query, so as to keep
        // compatibility with pre OGC 17-066r1 databases
        pszSQL = sqlite3_mprintf(
            "SELECT uom, field_name, grid_cell_encoding FROM "
            "gpkg_2d_gridded_coverage_ancillary "
            "WHERE tile_matrix_set_name = '%q'", pszTableName);
        CPLPushErrorHandler(CPLQuietErrorHandler);
        err = SQLQuery(hDB, pszSQL, &oResult);
        CPLPopErrorHandler();
        sqlite3_free(pszSQL);
        if( err == OGRERR_NONE && oResult.nRowCount == 1 )
        {
            const char* pszUom = SQLResultGetValue(&oResult, 0, 0);
            if( pszUom )
                osUom = pszUom;
            const char* pszFieldName = SQLResultGetValue(&oResult, 1, 0);
            if( pszFieldName )
                osFieldName = pszFieldName;
            const char* pszGridCellEncoding = SQLResultGetValue(&oResult, 2, 0);
            if( pszGridCellEncoding )
                osGridCellEncoding = pszGridCellEncoding;
        }
        SQLResultFree(&oResult);
    }

    m_bRecordInsertedInGPKGContent = true;
    m_nSRID = nSRSId;

    OGRSpatialReference* poSRS = GetSpatialRef( nSRSId );
    if( poSRS )
    {
        poSRS->exportToWkt(&m_pszProjection);
        poSRS->Release();
    }

    /* Various sanity checks added in the SELECT */
    char* pszQuotedTableName = sqlite3_mprintf("'%q'", pszTableName);
    CPLString osQuotedTableName(pszQuotedTableName);
    sqlite3_free(pszQuotedTableName);
    char* pszSQL = sqlite3_mprintf(
            "SELECT zoom_level, pixel_x_size, pixel_y_size, tile_width, "
            "tile_height, matrix_width, matrix_height "
            "FROM gpkg_tile_matrix tm "
            "WHERE table_name = %s "
            // INT_MAX would be the theoretical maximum value to avoid
            // overflows, but that's already a insane value.
            "AND zoom_level >= 0 AND zoom_level <= 65536 "
            "AND pixel_x_size > 0 AND pixel_y_size > 0 "
            "AND tile_width >= 1 AND tile_width <= 65536 "
            "AND tile_height >= 1 AND tile_height <= 65536 "
            "AND matrix_width >= 1 AND matrix_height >= 1",
            osQuotedTableName.c_str());
    CPLString osSQL(pszSQL);
    const char* pszZoomLevel =  CSLFetchNameValue(papszOpenOptionsIn, "ZOOM_LEVEL");
    if( pszZoomLevel )
    {
        if( bUpdate )
            osSQL += CPLSPrintf(" AND zoom_level <= %d", atoi(pszZoomLevel));
        else
        {
            osSQL += CPLSPrintf(" AND (zoom_level = %d OR (zoom_level < %d AND EXISTS(SELECT 1 FROM %s WHERE zoom_level = tm.zoom_level LIMIT 1)))",
                                atoi(pszZoomLevel), atoi(pszZoomLevel), osQuotedTableName.c_str());
        }
    }
    // In read-only mode, only lists non empty zoom levels
    else if( !bUpdate )
    {
        osSQL += CPLSPrintf(" AND EXISTS(SELECT 1 FROM %s WHERE zoom_level = tm.zoom_level LIMIT 1)",
                            osQuotedTableName.c_str());
    }
    else if( pszZoomLevel == nullptr )
    {
        osSQL += CPLSPrintf(" AND zoom_level <= (SELECT MAX(zoom_level) FROM %s)",
                            osQuotedTableName.c_str());
    }
    osSQL += " ORDER BY zoom_level DESC";
    // To avoid denial of service.
    osSQL += " LIMIT 100";

    err = SQLQuery(hDB, osSQL.c_str(), &oResult);
    if( err != OGRERR_NONE || oResult.nRowCount == 0 )
    {
        if( err == OGRERR_NONE && oResult.nRowCount == 0 &&
            pszContentsMinX != nullptr && pszContentsMinY != nullptr &&
            pszContentsMaxX != nullptr && pszContentsMaxY != nullptr )
        {
            SQLResultFree(&oResult);
            osSQL = pszSQL;
            osSQL += " ORDER BY zoom_level DESC";
            if( !bUpdate )
                osSQL += " LIMIT 1";
            err = SQLQuery(hDB, osSQL.c_str(), &oResult);
        }
        if( err != OGRERR_NONE || oResult.nRowCount == 0 )
        {
            if( err == OGRERR_NONE && pszZoomLevel != nullptr )
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "ZOOM_LEVEL is probably not valid w.r.t tile "
                         "table content");
            }
            SQLResultFree(&oResult);
            sqlite3_free(pszSQL);
            return false;
        }
    }
    sqlite3_free(pszSQL);

    // If USE_TILE_EXTENT=YES, then query the tile table to find which tiles
    // actually exist.

    // CAUTION: Do not move those variables inside inner scope !
    CPLString osContentsMinX, osContentsMinY, osContentsMaxX, osContentsMaxY;

    if( CPLTestBool(CSLFetchNameValueDef(papszOpenOptionsIn, "USE_TILE_EXTENT", "NO")) )
    {
        pszSQL = sqlite3_mprintf(
            "SELECT MIN(tile_column), MIN(tile_row), MAX(tile_column), MAX(tile_row) FROM \"%w\" WHERE zoom_level = %d",
            pszTableName, atoi(SQLResultGetValue(&oResult, 0, 0)));
        SQLResult oResult2;
        err = SQLQuery(hDB, pszSQL, &oResult2);
        sqlite3_free(pszSQL);
        if  ( err != OGRERR_NONE || oResult2.nRowCount == 0 ||
                // Can happen if table is empty
              SQLResultGetValue(&oResult2, 0, 0) == nullptr || 
                // Can happen if table has no NOT NULL constraint on tile_row
                // and that all tile_row are NULL
              SQLResultGetValue(&oResult2, 1, 0) == nullptr  )
        {
            SQLResultFree(&oResult);
            SQLResultFree(&oResult2);
            return false;
        }
        const double dfPixelXSize = CPLAtof(SQLResultGetValue(&oResult, 1, 0));
        const double dfPixelYSize = CPLAtof(SQLResultGetValue(&oResult, 2, 0));
        const int nTileWidth = atoi(SQLResultGetValue(&oResult, 3, 0));
        const int nTileHeight = atoi(SQLResultGetValue(&oResult, 4, 0));
        osContentsMinX = CPLSPrintf("%.18g", dfMinX + dfPixelXSize * nTileWidth * atoi(SQLResultGetValue(&oResult2, 0, 0)));
        osContentsMaxY = CPLSPrintf("%.18g", dfMaxY - dfPixelYSize * nTileHeight * atoi(SQLResultGetValue(&oResult2, 1, 0)));
        osContentsMaxX = CPLSPrintf("%.18g", dfMinX + dfPixelXSize * nTileWidth * (1 + atoi(SQLResultGetValue(&oResult2, 2, 0))));
        osContentsMinY = CPLSPrintf("%.18g", dfMaxY - dfPixelYSize * nTileHeight * (1 + atoi(SQLResultGetValue(&oResult2, 3, 0))));
        pszContentsMinX = osContentsMinX.c_str();
        pszContentsMinY = osContentsMinY.c_str();
        pszContentsMaxX = osContentsMaxX.c_str();
        pszContentsMaxY = osContentsMaxY.c_str();
        SQLResultFree(&oResult2);
    }

    if( !InitRaster(
            nullptr, pszTableName, dfMinX, dfMinY, dfMaxX, dfMaxY,
            pszContentsMinX, pszContentsMinY, pszContentsMaxX, pszContentsMaxY,
            papszOpenOptionsIn, oResult, 0) )
    {
        SQLResultFree(&oResult);
        return false;
    }

    auto poBand =
        reinterpret_cast<GDALGeoPackageRasterBand*>(GetRasterBand(1));
    if( !osDataNull.empty() )
    {
        double dfGPKGNoDataValue = CPLAtof(osDataNull);
        if( m_eTF == GPKG_TF_PNG_16BIT )
        {
            if( dfGPKGNoDataValue < 0 ||
                dfGPKGNoDataValue > 65535 ||
                static_cast<int>(dfGPKGNoDataValue) != dfGPKGNoDataValue )
            {
                CPLError(CE_Warning, CPLE_AppDefined,
                         "data_null = %.18g is invalid for integer data_type",
                         dfGPKGNoDataValue);
            }
            else
            {
                m_usGPKGNull = static_cast<GUInt16>(dfGPKGNoDataValue);
                if( m_eDT == GDT_Int16 && m_usGPKGNull > 32767 )
                    dfGPKGNoDataValue = -32768.0;
                poBand->SetNoDataValueInternal(dfGPKGNoDataValue);
            }
        }
        else
        {
            poBand->SetNoDataValueInternal(
                static_cast<float>(dfGPKGNoDataValue));
        }
    }
    if( !osUom.empty() )
    {
        poBand->SetUnitTypeInternal(osUom);
    }
    if( !osFieldName.empty() )
    {
        GetRasterBand(1)->GDALRasterBand::SetDescription(osFieldName);
    }
    if( !osGridCellEncoding.empty() )
    {
        if( osGridCellEncoding == "grid-value-is-center" )
        {
            GDALPamDataset::SetMetadataItem(GDALMD_AREA_OR_POINT,
                                            GDALMD_AOP_POINT);
        }
        else if( osGridCellEncoding == "grid-value-is-area" )
        {
            GDALPamDataset::SetMetadataItem(GDALMD_AREA_OR_POINT,
                                            GDALMD_AOP_AREA);
        }
        else
        {
            GDALPamDataset::SetMetadataItem(GDALMD_AREA_OR_POINT,
                                            GDALMD_AOP_POINT);
            GetRasterBand(1)->GDALRasterBand::SetMetadataItem(
                                                        "GRID_CELL_ENCODING",
                                                          osGridCellEncoding);
        }
    }

    CheckUnknownExtensions(true);

    // Do this after CheckUnknownExtensions() so that m_eTF is set to GPKG_TF_WEBP
    // if the table already registers the gpkg_webp extension
    const char* pszTF = CSLFetchNameValue(papszOpenOptionsIn, "TILE_FORMAT");
    if( pszTF )
    {
        if( !bUpdate )
        {
            CPLError(CE_Warning, CPLE_AppDefined,
                     "TILE_FORMAT open option ignored in read-only mode");
        }
        else if( m_eTF == GPKG_TF_PNG_16BIT ||
                 m_eTF == GPKG_TF_TIFF_32BIT_FLOAT )
        {
            CPLError(CE_Warning, CPLE_AppDefined,
                     "TILE_FORMAT open option ignored on gridded coverages");
        }
        else
        {
            GPKGTileFormat eTF = GDALGPKGMBTilesGetTileFormat(pszTF);
            if( eTF == GPKG_TF_WEBP && m_eTF != eTF )
            {
                if( !RegisterWebPExtension() )
                    return false;
            }
            m_eTF = eTF;
        }
    }

    ParseCompressionOptions(papszOpenOptionsIn);

    m_osWHERE = CSLFetchNameValueDef(papszOpenOptionsIn, "WHERE", "");

    // Set metadata
    if( pszIdentifier && pszIdentifier[0] )
        GDALPamDataset::SetMetadataItem("IDENTIFIER", pszIdentifier);
    if( pszDescription && pszDescription[0] )
        GDALPamDataset::SetMetadataItem("DESCRIPTION", pszDescription);

    // Add overviews
    for( int i = 1; i < oResult.nRowCount; i++ )
    {
        GDALGeoPackageDataset* poOvrDS = new GDALGeoPackageDataset();
        if( !poOvrDS->InitRaster(
            this, pszTableName, dfMinX, dfMinY, dfMaxX, dfMaxY,
            pszContentsMinX, pszContentsMinY, pszContentsMaxX, pszContentsMaxY,
            papszOpenOptionsIn, oResult, i) )
        {
            delete poOvrDS;
            break;
        }

        m_papoOverviewDS = (GDALGeoPackageDataset**) CPLRealloc(m_papoOverviewDS,
                        sizeof(GDALGeoPackageDataset*) * (m_nOverviewCount+1));
        m_papoOverviewDS[m_nOverviewCount ++] = poOvrDS;

        int nTileWidth, nTileHeight;
        poOvrDS->GetRasterBand(1)->GetBlockSize(&nTileWidth, &nTileHeight);
        if( eAccess == GA_ReadOnly &&
            poOvrDS->GetRasterXSize() < nTileWidth &&
            poOvrDS->GetRasterYSize() < nTileHeight )
        {
            break;
        }
    }

    SQLResultFree(&oResult);

    return true;
}

/************************************************************************/
/*                         GetProjectionRef()                           */
/************************************************************************/

const char* GDALGeoPackageDataset::_GetProjectionRef()
{
    return (m_pszProjection) ? m_pszProjection : "";
}

/************************************************************************/
/*                           SetProjection()                            */
/************************************************************************/

CPLErr GDALGeoPackageDataset::_SetProjection( const char* pszProjection )
{
    if( nBands == 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "SetProjection() not supported on a dataset with 0 band");
        return CE_Failure;
    }
    if( eAccess != GA_Update )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "SetProjection() not supported on read-only dataset");
        return CE_Failure;
    }

    int nSRID = -1;
    if( pszProjection == nullptr || pszProjection[0] == '\0' )
    {
      // nSRID = -1;
    }
    else
    {
        OGRSpatialReference oSRS;
        if( oSRS.SetFromUserInput(pszProjection) != OGRERR_NONE )
            return CE_Failure;
        nSRID = GetSrsId( oSRS );
    }

    for(size_t iScheme = 0;
               iScheme < sizeof(asTilingShemes)/sizeof(asTilingShemes[0]);
               iScheme++ )
    {
        if( EQUAL(m_osTilingScheme, asTilingShemes[iScheme].pszName) )
        {
            if( nSRID != asTilingShemes[iScheme].nEPSGCode )
            {
                CPLError(CE_Failure, CPLE_NotSupported,
                        "Projection should be EPSG:%d for %s tiling scheme",
                         asTilingShemes[iScheme].nEPSGCode,
                         m_osTilingScheme.c_str());
                return CE_Failure;
            }
        }
    }

    m_nSRID = nSRID;
    CPLFree(m_pszProjection);
    m_pszProjection = pszProjection ? CPLStrdup(pszProjection) : CPLStrdup("");

    if( m_bRecordInsertedInGPKGContent )
    {
        char* pszSQL = sqlite3_mprintf("UPDATE gpkg_contents SET srs_id = %d WHERE lower(table_name) = lower('%q')",
                                        m_nSRID, m_osRasterTable.c_str());
        OGRErr eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
        if ( eErr != OGRERR_NONE )
            return CE_Failure;

        pszSQL = sqlite3_mprintf("UPDATE gpkg_tile_matrix_set SET srs_id = %d WHERE lower(table_name) = lower('%q')",
                                 m_nSRID, m_osRasterTable.c_str());
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
        if ( eErr != OGRERR_NONE )
            return CE_Failure;
    }

    return CE_None;
}

/************************************************************************/
/*                          GetGeoTransform()                           */
/************************************************************************/

CPLErr GDALGeoPackageDataset::GetGeoTransform( double* padfGeoTransform )
{
    memcpy(padfGeoTransform, m_adfGeoTransform, 6 * sizeof(double));
    if( !m_bGeoTransformValid )
        return CE_Failure;
    else
        return CE_None;
}

/************************************************************************/
/*                          SetGeoTransform()                           */
/************************************************************************/

CPLErr GDALGeoPackageDataset::SetGeoTransform( double* padfGeoTransform )
{
    if( nBands == 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "SetGeoTransform() not supported on a dataset with 0 band");
        return CE_Failure;
    }
    if( eAccess != GA_Update )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "SetGeoTransform() not supported on read-only dataset");
        return CE_Failure;
    }
    if( m_bGeoTransformValid )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Cannot modify geotransform once set");
        return CE_Failure;
    }
    if( padfGeoTransform[2] != 0.0 || padfGeoTransform[4] != 0 ||
        padfGeoTransform[5] > 0.0 )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Only north-up non rotated geotransform supported");
        return CE_Failure;
    }

    for(size_t iScheme = 0;
               iScheme < sizeof(asTilingShemes)/sizeof(asTilingShemes[0]);
               iScheme++ )
    {
        if( EQUAL(m_osTilingScheme, asTilingShemes[iScheme].pszName) )
        {
            double dfPixelXSizeZoomLevel0 = asTilingShemes[iScheme].dfPixelXSizeZoomLevel0;
            double dfPixelYSizeZoomLevel0 = asTilingShemes[iScheme].dfPixelYSizeZoomLevel0;
            for( m_nZoomLevel = 0; m_nZoomLevel < 25; m_nZoomLevel++ )
            {
                double dfExpectedPixelXSize = dfPixelXSizeZoomLevel0 / (1 << m_nZoomLevel);
                double dfExpectedPixelYSize = dfPixelYSizeZoomLevel0 / (1 << m_nZoomLevel);
                if( fabs( padfGeoTransform[1] - dfExpectedPixelXSize ) < 1e-8 * dfExpectedPixelXSize &&
                    fabs( fabs(padfGeoTransform[5]) - dfExpectedPixelYSize ) < 1e-8 * dfExpectedPixelYSize )
                {
                    break;
                }
            }
            if( m_nZoomLevel == 25 )
            {
                m_nZoomLevel = -1;
                CPLError(CE_Failure, CPLE_NotSupported,
                         "Could not find an appropriate zoom level of %s tiling scheme that matches raster pixel size",
                         m_osTilingScheme.c_str());
                return CE_Failure;
            }
            break;
        }
    }

    memcpy(m_adfGeoTransform, padfGeoTransform, 6 * sizeof(double));
    m_bGeoTransformValid = true;

    return FinalizeRasterRegistration();
}

/************************************************************************/
/*                      FinalizeRasterRegistration()                    */
/************************************************************************/

CPLErr GDALGeoPackageDataset::FinalizeRasterRegistration()
{
    OGRErr eErr;

    m_dfTMSMinX = m_adfGeoTransform[0];
    m_dfTMSMaxY = m_adfGeoTransform[3];

    int nTileWidth, nTileHeight;
    GetRasterBand(1)->GetBlockSize(&nTileWidth, &nTileHeight);

    if( m_nZoomLevel < 0 )
    {
        m_nZoomLevel = 0;
        while( (nRasterXSize >> m_nZoomLevel) > nTileWidth ||
            (nRasterYSize >> m_nZoomLevel) > nTileHeight )
            m_nZoomLevel ++;
    }

    double dfPixelXSizeZoomLevel0 = m_adfGeoTransform[1] * (1 << m_nZoomLevel);
    double dfPixelYSizeZoomLevel0 = fabs(m_adfGeoTransform[5]) * (1 << m_nZoomLevel);
    int nTileXCountZoomLevel0 =
        std::max(1, DIV_ROUND_UP((nRasterXSize >> m_nZoomLevel), nTileWidth));
    int nTileYCountZoomLevel0 =
        std::max(1, DIV_ROUND_UP((nRasterYSize >> m_nZoomLevel), nTileHeight));

    for(size_t iScheme = 0;
               iScheme < sizeof(asTilingShemes)/sizeof(asTilingShemes[0]);
               iScheme++ )
    {
        if( EQUAL(m_osTilingScheme, asTilingShemes[iScheme].pszName) )
        {
            CPLAssert( m_nZoomLevel >= 0 );
            m_dfTMSMinX = asTilingShemes[iScheme].dfMinX;
            m_dfTMSMaxY = asTilingShemes[iScheme].dfMaxY;
            dfPixelXSizeZoomLevel0 = asTilingShemes[iScheme].dfPixelXSizeZoomLevel0;
            dfPixelYSizeZoomLevel0 = asTilingShemes[iScheme].dfPixelYSizeZoomLevel0;
            nTileXCountZoomLevel0 = asTilingShemes[iScheme].nTileXCountZoomLevel0;
            nTileYCountZoomLevel0 = asTilingShemes[iScheme].nTileYCountZoomLevel0;
            break;
        }
    }
    m_nTileMatrixWidth = nTileXCountZoomLevel0 * (1 << m_nZoomLevel);
    m_nTileMatrixHeight = nTileYCountZoomLevel0 * (1 << m_nZoomLevel);

    if( !ComputeTileAndPixelShifts() )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Overflow occurred in ComputeTileAndPixelShifts()");
        return CE_Failure;
    }

    if( !AllocCachedTiles() )
    {
        return CE_Failure;
    }

    double dfGDALMinX = m_adfGeoTransform[0];
    double dfGDALMinY = m_adfGeoTransform[3] + nRasterYSize * m_adfGeoTransform[5];
    double dfGDALMaxX = m_adfGeoTransform[0] + nRasterXSize * m_adfGeoTransform[1];
    double dfGDALMaxY = m_adfGeoTransform[3];

    SoftStartTransaction();

    const char* pszCurrentDate = CPLGetConfigOption("OGR_CURRENT_DATE", nullptr);
    CPLString osInsertGpkgContentsFormatting("INSERT INTO gpkg_contents "
            "(table_name,data_type,identifier,description,min_x,min_y,max_x,max_y,last_change,srs_id) VALUES "
            "('%q','%q','%q','%q',%.18g,%.18g,%.18g,%.18g,");
    osInsertGpkgContentsFormatting += ( pszCurrentDate ) ? "'%q'" : "%s";
    osInsertGpkgContentsFormatting += ",%d)";
    char* pszSQL =
        sqlite3_mprintf(osInsertGpkgContentsFormatting.c_str(),
        m_osRasterTable.c_str(),
        (m_eDT == GDT_Byte) ? "tiles" : "2d-gridded-coverage",
        m_osIdentifier.c_str(),
        m_osDescription.c_str(),
        dfGDALMinX, dfGDALMinY, dfGDALMaxX, dfGDALMaxY,
        pszCurrentDate ? pszCurrentDate : "strftime('%Y-%m-%dT%H:%M:%fZ','now')",
        m_nSRID);

    eErr = SQLCommand(hDB, pszSQL);
    sqlite3_free(pszSQL);
    if ( eErr != OGRERR_NONE )
        return CE_Failure;

    double dfTMSMaxX = m_dfTMSMinX + nTileXCountZoomLevel0 * nTileWidth * dfPixelXSizeZoomLevel0;
    double dfTMSMinY = m_dfTMSMaxY - nTileYCountZoomLevel0 * nTileHeight * dfPixelYSizeZoomLevel0;

    pszSQL = sqlite3_mprintf("INSERT INTO gpkg_tile_matrix_set "
            "(table_name,srs_id,min_x,min_y,max_x,max_y) VALUES "
            "('%q',%d,%.18g,%.18g,%.18g,%.18g)",
            m_osRasterTable.c_str(), m_nSRID,
            m_dfTMSMinX,dfTMSMinY,dfTMSMaxX,m_dfTMSMaxY);
    eErr = SQLCommand(hDB, pszSQL);
    sqlite3_free(pszSQL);
    if ( eErr != OGRERR_NONE )
        return CE_Failure;

    m_papoOverviewDS = (GDALGeoPackageDataset**) CPLCalloc(sizeof(GDALGeoPackageDataset*),
                                                           m_nZoomLevel);

    for( int i = 0; i <= m_nZoomLevel; i++ )
    {
        double dfPixelXSizeZoomLevel = 0.0;
        double dfPixelYSizeZoomLevel = 0.0;
        int nTileMatrixWidth = 0;
        int nTileMatrixHeight = 0;
        if( EQUAL(m_osTilingScheme, "CUSTOM") )
        {
            dfPixelXSizeZoomLevel = m_adfGeoTransform[1] * (1 << (m_nZoomLevel-i));
            dfPixelYSizeZoomLevel = fabs(m_adfGeoTransform[5]) * (1 << (m_nZoomLevel-i));
        }
        else
        {
            dfPixelXSizeZoomLevel = dfPixelXSizeZoomLevel0 / (1 << i);
            dfPixelYSizeZoomLevel = dfPixelYSizeZoomLevel0 / (1 << i);
        }
        nTileMatrixWidth = nTileXCountZoomLevel0 * (1 << i);
        nTileMatrixHeight = nTileYCountZoomLevel0 * (1 << i);

        pszSQL = sqlite3_mprintf("INSERT INTO gpkg_tile_matrix "
                "(table_name,zoom_level,matrix_width,matrix_height,tile_width,tile_height,pixel_x_size,pixel_y_size) VALUES "
                "('%q',%d,%d,%d,%d,%d,%.18g,%.18g)",
                m_osRasterTable.c_str(),i,nTileMatrixWidth,nTileMatrixHeight,
                nTileWidth,nTileHeight,dfPixelXSizeZoomLevel,dfPixelYSizeZoomLevel);
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
        if ( eErr != OGRERR_NONE )
            return CE_Failure;

        if( i < m_nZoomLevel )
        {
            GDALGeoPackageDataset* poOvrDS = new GDALGeoPackageDataset();
            poOvrDS->InitRaster( this, m_osRasterTable, i, nBands,
                                 m_dfTMSMinX, m_dfTMSMaxY,
                                 dfPixelXSizeZoomLevel, dfPixelYSizeZoomLevel,
                                 nTileWidth, nTileHeight,
                                 nTileMatrixWidth,nTileMatrixHeight,
                                 dfGDALMinX, dfGDALMinY,
                                 dfGDALMaxX, dfGDALMaxY );

            m_papoOverviewDS[m_nZoomLevel-1-i] = poOvrDS;
        }
    }

    SoftCommitTransaction();

    m_nOverviewCount = m_nZoomLevel;
    m_bRecordInsertedInGPKGContent = true;

    return CE_None;
}

/************************************************************************/
/*                             FlushCache()                             */
/************************************************************************/

void GDALGeoPackageDataset::FlushCache()
{
    IFlushCacheWithErrCode();
}

CPLErr GDALGeoPackageDataset::IFlushCacheWithErrCode()

{
    if( m_bInFlushCache )
        return CE_None;
    m_bInFlushCache = true;
    // Short circuit GDALPamDataset to avoid serialization to .aux.xml
    GDALDataset::FlushCache();

    for( int i = 0; i < m_nLayers; i++ )
    {
        m_papoLayers[i]->RunDeferredCreationIfNecessary();
        m_papoLayers[i]->CreateSpatialIndexIfNecessary();
    }

    // Update raster table last_change column in gpkg_contents if needed
    if( m_bHasModifiedTiles )
    {
        UpdateGpkgContentsLastChange(m_osRasterTable);

        m_bHasModifiedTiles = false;
    }

    CPLErr eErr = FlushTiles();

    m_bInFlushCache = false;
    return eErr;
}

/************************************************************************/
/*                    UpdateGpkgContentsLastChange()                    */
/************************************************************************/

OGRErr GDALGeoPackageDataset::UpdateGpkgContentsLastChange(
                                                const char* pszTableName)
{
    const char* pszCurrentDate = CPLGetConfigOption("OGR_CURRENT_DATE", nullptr);
    char *pszSQL = nullptr ;

    if( pszCurrentDate )
    {
        pszSQL = sqlite3_mprintf(
                    "UPDATE gpkg_contents SET "
                    "last_change = '%q'"
                    "WHERE lower(table_name) = lower('%q')",
                    pszCurrentDate,
                    pszTableName);
    }
    else
    {
        pszSQL = sqlite3_mprintf(
                    "UPDATE gpkg_contents SET "
                    "last_change = strftime('%%Y-%%m-%%dT%%H:%%M:%%fZ','now')"
                    "WHERE lower(table_name) = lower('%q')",
                    pszTableName);
    }

    OGRErr eErr = SQLCommand(hDB, pszSQL);
    sqlite3_free(pszSQL);
    return eErr;
}

/************************************************************************/
/*                          IBuildOverviews()                           */
/************************************************************************/

static int GetFloorPowerOfTwo(int n)
{
    int p2 = 1;
    while( (n = n >> 1) > 0 )
    {
        p2 <<= 1;
    }
    return p2;
}

CPLErr GDALGeoPackageDataset::IBuildOverviews(
                        const char * pszResampling,
                        int nOverviews, int * panOverviewList,
                        int nBandsIn, int * /*panBandList*/,
                        GDALProgressFunc pfnProgress, void * pProgressData )
{
    if( GetAccess() != GA_Update )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Overview building not supported on a database opened in read-only mode");
        return CE_Failure;
    }
    if( m_poParentDS != nullptr )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Overview building not supported on overview dataset");
        return CE_Failure;
    }

    if( nOverviews == 0 )
    {
        for(int i=0;i<m_nOverviewCount;i++)
            m_papoOverviewDS[i]->FlushCache();

        SoftStartTransaction();

        if( m_eTF == GPKG_TF_PNG_16BIT ||
            m_eTF == GPKG_TF_TIFF_32BIT_FLOAT )
        {
            char* pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_2d_gridded_tile_ancillary WHERE id IN "
                "(SELECT y.id FROM \"%w\" x "
                "JOIN gpkg_2d_gridded_tile_ancillary y "
                "ON x.id = y.tpudt_id AND y.tpudt_name = '%q' AND "
                "x.zoom_level < %d)",
                m_osRasterTable.c_str(), m_osRasterTable.c_str(), m_nZoomLevel);
            OGRErr eErr = SQLCommand(hDB, pszSQL);
            sqlite3_free(pszSQL);
            if( eErr != OGRERR_NONE )
            {
                SoftRollbackTransaction();
                return CE_Failure;
            }
        }

        char* pszSQL = sqlite3_mprintf("DELETE FROM \"%w\" WHERE zoom_level < %d",
                                       m_osRasterTable.c_str(),
                                       m_nZoomLevel);
        OGRErr eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
        if( eErr != OGRERR_NONE )
        {
            SoftRollbackTransaction();
            return CE_Failure;
        }

        SoftCommitTransaction();

        return CE_None;
    }

    if( nBandsIn != nBands )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Generation of overviews in GPKG only"
                  "supported when operating on all bands." );
        return CE_Failure;
    }

    if( m_nOverviewCount == 0 )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Image too small to support overviews");
        return CE_Failure;
    }

    FlushCache();
    for(int i=0;i<nOverviews;i++)
    {
        if( panOverviewList[i] < 2 )
        {
            CPLError(CE_Failure, CPLE_IllegalArg, "Overview factor must be >= 2");
            return CE_Failure;
        }

        bool bFound = false;
        int jCandidate = -1;
        int nMaxOvFactor = 0;
        for( int j = 0; j < m_nOverviewCount; j++ )
        {
            GDALDataset* poODS = m_papoOverviewDS[j];

            int nOvFactor = GDALComputeOvFactor(poODS->GetRasterXSize(),
                                                GetRasterXSize(),
                                                poODS->GetRasterYSize(),
                                                GetRasterYSize());
            if( GetRasterXSize() / panOverviewList[i] == poODS->GetRasterXSize() &&
                GetRasterYSize() / panOverviewList[i] == poODS->GetRasterYSize() )
            {
                nOvFactor = panOverviewList[i];
            }
            else if( nOvFactor == GDALOvLevelAdjust2( panOverviewList[i],
                                                      GetRasterXSize(),
                                                      GetRasterYSize() ) )
            {
                nOvFactor = panOverviewList[i];
            }
            else if( nOvFactor > 64 &&
                     std::abs(nOvFactor - GetFloorPowerOfTwo(nOvFactor+2)) <= 2 )
            {
                nOvFactor = GetFloorPowerOfTwo(nOvFactor+2);
            }

            nMaxOvFactor = nOvFactor;

            if( nOvFactor == panOverviewList[i] )
            {
                bFound = true;
                break;
            }

            if( jCandidate < 0 && nOvFactor > panOverviewList[i] )
                jCandidate = j;
        }

        if( !bFound )
        {
            /* Mostly for debug */
            if( !CPLTestBool(CPLGetConfigOption("ALLOW_GPKG_ZOOM_OTHER_EXTENSION", "YES")) )
            {
                CPLString osOvrList;
                for(int j=0;j<m_nOverviewCount;j++)
                {
                    GDALDataset* poODS = m_papoOverviewDS[j];

                    /* Compute overview factor */
                    int nOvFactor = (int)
                        (0.5 + GetRasterXSize() / (double) poODS->GetRasterXSize());
                    int nODSXSize = (int)(0.5 + GetRasterXSize() / (double) nOvFactor);
                    if( nODSXSize != poODS->GetRasterXSize() )
                    {
                        int nOvFactorPowerOfTwo = GetFloorPowerOfTwo(nOvFactor);
                        nODSXSize = (int)(0.5 + GetRasterXSize() / (double) nOvFactorPowerOfTwo);
                        if( nODSXSize == poODS->GetRasterXSize() )
                            nOvFactor = nOvFactorPowerOfTwo;
                        else
                        {
                            nOvFactorPowerOfTwo <<= 1;
                            nODSXSize = (int)(0.5 + GetRasterXSize() / (double) nOvFactorPowerOfTwo);
                            if( nODSXSize == poODS->GetRasterXSize() )
                                nOvFactor = nOvFactorPowerOfTwo;
                        }
                    }
                    if( j != 0 )
                        osOvrList += " ";
                    osOvrList += CPLSPrintf("%d", nOvFactor);
                }
                CPLError(CE_Failure, CPLE_NotSupported,
                        "Only overviews %s can be computed", osOvrList.c_str());
                return CE_Failure;
            }
            else
            {
                int nOvFactor = panOverviewList[i];
                if( jCandidate < 0 )
                    jCandidate = m_nOverviewCount;

                int nOvXSize = GetRasterXSize() / nOvFactor;
                int nOvYSize = GetRasterYSize() / nOvFactor;
                if( nOvXSize < 8 || nOvYSize < 8)
                {
                    CPLError(CE_Failure, CPLE_NotSupported,
                             "Too big overview factor : %d. Would result in a %dx%d overview",
                             nOvFactor, nOvXSize, nOvYSize);
                    return CE_Failure;
                }
                if( !(jCandidate == m_nOverviewCount && nOvFactor == 2 * nMaxOvFactor) &&
                    !m_bZoomOther )
                {
                    CPLError(CE_Warning, CPLE_AppDefined,
                            "Use of overview factor %d causes gpkg_zoom_other extension to be needed",
                            nOvFactor);
                    RegisterZoomOtherExtension();
                    m_bZoomOther = true;
                }

                SoftStartTransaction();

                CPLAssert(jCandidate > 0);
                int nNewZoomLevel = m_papoOverviewDS[jCandidate-1]->m_nZoomLevel;

                char* pszSQL;
                OGRErr eErr;
                for(int k=0;k<=jCandidate;k++)
                {
                    pszSQL = sqlite3_mprintf("UPDATE gpkg_tile_matrix SET zoom_level = %d "
                        "WHERE lower(table_name) = lower('%q') AND zoom_level = %d",
                        m_nZoomLevel - k + 1,
                        m_osRasterTable.c_str(),
                        m_nZoomLevel - k);
                    eErr = SQLCommand(hDB, pszSQL);
                    sqlite3_free(pszSQL);
                    if ( eErr != OGRERR_NONE )
                    {
                        SoftRollbackTransaction();
                        return CE_Failure;
                    }

                    pszSQL = sqlite3_mprintf("UPDATE \"%w\" SET zoom_level = %d "
                        "WHERE zoom_level = %d",
                        m_osRasterTable.c_str(),
                        m_nZoomLevel - k + 1,
                        m_nZoomLevel - k);
                    eErr = SQLCommand(hDB, pszSQL);
                    sqlite3_free(pszSQL);
                    if ( eErr != OGRERR_NONE )
                    {
                        SoftRollbackTransaction();
                        return CE_Failure;
                    }
                }

                double dfGDALMinX = m_adfGeoTransform[0];
                double dfGDALMinY = m_adfGeoTransform[3] + nRasterYSize * m_adfGeoTransform[5];
                double dfGDALMaxX = m_adfGeoTransform[0] + nRasterXSize * m_adfGeoTransform[1];
                double dfGDALMaxY = m_adfGeoTransform[3];
                double dfPixelXSizeZoomLevel = m_adfGeoTransform[1] * nOvFactor;
                double dfPixelYSizeZoomLevel = fabs(m_adfGeoTransform[5]) * nOvFactor;
                int nTileWidth, nTileHeight;
                GetRasterBand(1)->GetBlockSize(&nTileWidth, &nTileHeight);
                int nTileMatrixWidth = (nOvXSize + nTileWidth - 1) / nTileWidth;
                int nTileMatrixHeight = (nOvYSize + nTileHeight - 1) / nTileHeight;
                pszSQL = sqlite3_mprintf("INSERT INTO gpkg_tile_matrix "
                        "(table_name,zoom_level,matrix_width,matrix_height,tile_width,tile_height,pixel_x_size,pixel_y_size) VALUES "
                        "('%q',%d,%d,%d,%d,%d,%.18g,%.18g)",
                        m_osRasterTable.c_str(),nNewZoomLevel,nTileMatrixWidth,nTileMatrixHeight,
                        nTileWidth,nTileHeight,dfPixelXSizeZoomLevel,dfPixelYSizeZoomLevel);
                eErr = SQLCommand(hDB, pszSQL);
                sqlite3_free(pszSQL);
                if ( eErr != OGRERR_NONE )
                {
                    SoftRollbackTransaction();
                    return CE_Failure;
                }

                SoftCommitTransaction();

                m_nZoomLevel ++; /* this change our zoom level as well as previous overviews */
                for(int k=0;k<jCandidate;k++)
                    m_papoOverviewDS[k]->m_nZoomLevel ++;

                GDALGeoPackageDataset* poOvrDS = new GDALGeoPackageDataset();
                poOvrDS->InitRaster(
                    this, m_osRasterTable,
                    nNewZoomLevel, nBands,
                    m_dfTMSMinX, m_dfTMSMaxY,
                    dfPixelXSizeZoomLevel, dfPixelYSizeZoomLevel,
                    nTileWidth, nTileHeight,
                    nTileMatrixWidth,nTileMatrixHeight,
                    dfGDALMinX, dfGDALMinY,
                    dfGDALMaxX, dfGDALMaxY );
                m_papoOverviewDS = (GDALGeoPackageDataset**) CPLRealloc(
                    m_papoOverviewDS, sizeof(GDALGeoPackageDataset*) * (m_nOverviewCount+1));

                if( jCandidate < m_nOverviewCount )
                {
                    memmove(m_papoOverviewDS + jCandidate + 1,
                            m_papoOverviewDS + jCandidate,
                            sizeof(GDALGeoPackageDataset*) * (m_nOverviewCount-jCandidate));
                }
                m_papoOverviewDS[jCandidate] = poOvrDS;
                m_nOverviewCount ++;
            }
        }
    }

    GDALRasterBand*** papapoOverviewBands = (GDALRasterBand ***) CPLCalloc(sizeof(void*),nBands);
    CPLErr eErr = CE_None;
    for( int iBand = 0; eErr == CE_None && iBand < nBands; iBand++ )
    {
        papapoOverviewBands[iBand] = (GDALRasterBand **) CPLCalloc(sizeof(void*),nOverviews);
        int iCurOverview = 0;
        for(int i=0;i<nOverviews;i++)
        {
            int j = 0;  // Used after for.
            for( ; j < m_nOverviewCount; j++ )
            {
                GDALDataset* poODS = m_papoOverviewDS[j];

                int nOvFactor =
                    GDALComputeOvFactor(poODS->GetRasterXSize(),
                                        GetRasterXSize(),
                                        poODS->GetRasterYSize(),
                                        GetRasterYSize());
                if( GetRasterXSize() / panOverviewList[i] == poODS->GetRasterXSize() &&
                    GetRasterYSize() / panOverviewList[i] == poODS->GetRasterYSize() )
                {
                    nOvFactor = panOverviewList[i];
                }
                else if( nOvFactor == GDALOvLevelAdjust2( panOverviewList[i],
                                                        GetRasterXSize(),
                                                        GetRasterYSize() ) )
                {
                    nOvFactor = panOverviewList[i];
                }
                else if( nOvFactor > 64 &&
                        std::abs(nOvFactor - GetFloorPowerOfTwo(nOvFactor+2)) <= 2 )
                {
                    nOvFactor = GetFloorPowerOfTwo(nOvFactor+2);
                }

                if( nOvFactor == panOverviewList[i] )
                {
                    papapoOverviewBands[iBand][iCurOverview] = poODS->GetRasterBand(iBand+1);
                    iCurOverview++ ;
                    break;
                }
            }
            if( j == m_nOverviewCount )
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "Could not find dataset corresponding to ov factor %d",
                         panOverviewList[i]);
                eErr = CE_Failure;
            }
        }
        if( eErr == CE_None )
        {
            CPLAssert(iCurOverview == nOverviews);
        }
    }

    if( eErr == CE_None )
        eErr = GDALRegenerateOverviewsMultiBand(nBands, papoBands,
                                     nOverviews, papapoOverviewBands,
                                     pszResampling, pfnProgress, pProgressData );

    for( int iBand = 0; iBand < nBands; iBand++ )
    {
        CPLFree(papapoOverviewBands[iBand]);
    }
    CPLFree(papapoOverviewBands);

    return eErr;
}

/************************************************************************/
/*                      GetMetadataDomainList()                         */
/************************************************************************/

char **GDALGeoPackageDataset::GetMetadataDomainList()
{
    GetMetadata();
    if( !m_osRasterTable.empty() )
        GetMetadata("GEOPACKAGE");
    return BuildMetadataDomainList(GDALPamDataset::GetMetadataDomainList(),
                                   TRUE,
                                   "SUBDATASETS", nullptr);
}

/************************************************************************/
/*                        CheckMetadataDomain()                         */
/************************************************************************/

const char* GDALGeoPackageDataset::CheckMetadataDomain( const char* pszDomain )
{
    if( pszDomain != nullptr && EQUAL(pszDomain, "GEOPACKAGE") &&
        m_osRasterTable.empty() )
    {
        CPLError(CE_Warning, CPLE_IllegalArg,
                 "Using GEOPACKAGE for a non-raster geopackage is not supported. "
                 "Using default domain instead");
        return nullptr;
    }
    return pszDomain;
}

/************************************************************************/
/*                           HasMetadataTables()                        */
/************************************************************************/

bool GDALGeoPackageDataset::HasMetadataTables()
{
    const int nCount = SQLGetInteger(hDB,
                  "SELECT COUNT(*) FROM sqlite_master WHERE name IN "
                  "('gpkg_metadata', 'gpkg_metadata_reference') "
                  "AND type IN ('table', 'view')", nullptr);
    return nCount == 2;
}

/************************************************************************/
/*                         HasDataColumnsTable()                        */
/************************************************************************/

bool GDALGeoPackageDataset::HasDataColumnsTable()
{
    const int nCount = SQLGetInteger(hDB,
                "SELECT 1 FROM sqlite_master WHERE name = 'gpkg_data_columns'"
                "AND type IN ('table', 'view')", nullptr);
    return nCount == 1;
}

/************************************************************************/
/*                    HasDataColumnConstraintsTable()                   */
/************************************************************************/

bool GDALGeoPackageDataset::HasDataColumnConstraintsTable()
{
    const int nCount = SQLGetInteger(hDB,
    "SELECT 1 FROM sqlite_master WHERE name = 'gpkg_data_column_constraints'"
    "AND type IN ('table', 'view')", nullptr);
    return nCount == 1;
}

/************************************************************************/
/*                            GetMetadata()                             */
/************************************************************************/

char **GDALGeoPackageDataset::GetMetadata( const char *pszDomain )

{
    pszDomain = CheckMetadataDomain(pszDomain);
    if( pszDomain != nullptr && EQUAL(pszDomain,"SUBDATASETS") )
        return m_papszSubDatasets;

    if( m_bHasReadMetadataFromStorage )
        return GDALPamDataset::GetMetadata( pszDomain );

    m_bHasReadMetadataFromStorage = true;

    if( !HasMetadataTables() )
        return GDALPamDataset::GetMetadata( pszDomain );

    char* pszSQL = nullptr;
    if( !m_osRasterTable.empty() )
    {
        pszSQL = sqlite3_mprintf(
            "SELECT md.metadata, md.md_standard_uri, md.mime_type, "
            "mdr.reference_scope FROM gpkg_metadata md "
            "JOIN gpkg_metadata_reference mdr ON (md.id = mdr.md_file_id ) "
            "WHERE md.metadata IS NOT NULL AND "
            "md.md_standard_uri IS NOT NULL AND "
            "md.mime_type IS NOT NULL AND "
            "(mdr.reference_scope = 'geopackage' OR "
            "(mdr.reference_scope = 'table' AND lower(mdr.table_name) = lower('%q'))) ORDER BY md.id "
            "LIMIT 1000", // to avoid denial of service
            m_osRasterTable.c_str());
    }
    else
    {
        pszSQL = sqlite3_mprintf(
            "SELECT md.metadata, md.md_standard_uri, md.mime_type, "
            "mdr.reference_scope FROM gpkg_metadata md "
            "JOIN gpkg_metadata_reference mdr ON (md.id = mdr.md_file_id ) "
            "WHERE md.metadata IS NOT NULL AND "
            "md.md_standard_uri IS NOT NULL AND "
            "md.mime_type IS NOT NULL AND "
            "mdr.reference_scope = 'geopackage' ORDER BY md.id "
            "LIMIT 1000" // to avoid denial of service
        );
    }

    SQLResult oResult;
    OGRErr err = SQLQuery(hDB, pszSQL, &oResult);
    sqlite3_free(pszSQL);
    if  ( err != OGRERR_NONE )
    {
        SQLResultFree(&oResult);
        return GDALPamDataset::GetMetadata( pszDomain );
    }

    char** papszMetadata = CSLDuplicate(GDALPamDataset::GetMetadata());

    /* GDAL metadata */
    for(int i=0;i<oResult.nRowCount;i++)
    {
        const char *pszMetadata = SQLResultGetValue(&oResult, 0, i);
        const char* pszMDStandardURI = SQLResultGetValue(&oResult, 1, i);
        const char* pszMimeType = SQLResultGetValue(&oResult, 2, i);
        const char* pszReferenceScope = SQLResultGetValue(&oResult, 3, i);
        int bIsGPKGScope = EQUAL(pszReferenceScope, "geopackage");
        if( EQUAL(pszMDStandardURI, "http://gdal.org") &&
            EQUAL(pszMimeType, "text/xml") )
        {
            CPLXMLNode* psXMLNode = CPLParseXMLString(pszMetadata);
            if( psXMLNode )
            {
                GDALMultiDomainMetadata oLocalMDMD;
                oLocalMDMD.XMLInit(psXMLNode, FALSE);
                if( !m_osRasterTable.empty() && bIsGPKGScope )
                {
                    oMDMD.SetMetadata( oLocalMDMD.GetMetadata(), "GEOPACKAGE" );
                }
                else
                {
                    papszMetadata = CSLMerge(papszMetadata, oLocalMDMD.GetMetadata());
                    char** papszDomainList = oLocalMDMD.GetDomainList();
                    char** papszIter = papszDomainList;
                    while( papszIter && *papszIter )
                    {
                        if( !EQUAL(*papszIter, "") && !EQUAL(*papszIter, "IMAGE_STRUCTURE") )
                            oMDMD.SetMetadata(oLocalMDMD.GetMetadata(*papszIter), *papszIter);
                        papszIter ++;
                    }
                }
                CPLDestroyXMLNode(psXMLNode);
            }
        }
    }

    GDALPamDataset::SetMetadata(papszMetadata);
    CSLDestroy(papszMetadata);
    papszMetadata = nullptr;

    /* Add non-GDAL metadata now */
    int nNonGDALMDILocal = 1;
    int nNonGDALMDIGeopackage = 1;
    for(int i=0;i<oResult.nRowCount;i++)
    {
        const char *pszMetadata = SQLResultGetValue(&oResult, 0, i);
        const char* pszMDStandardURI = SQLResultGetValue(&oResult, 1, i);
        const char* pszMimeType = SQLResultGetValue(&oResult, 2, i);
        const char* pszReferenceScope = SQLResultGetValue(&oResult, 3, i);
        int bIsGPKGScope = EQUAL(pszReferenceScope, "geopackage");
        if( EQUAL(pszMDStandardURI, "http://gdal.org") &&
            EQUAL(pszMimeType, "text/xml") )
            continue;

        if( !m_osRasterTable.empty() && bIsGPKGScope )
        {
            oMDMD.SetMetadataItem( CPLSPrintf("GPKG_METADATA_ITEM_%d", nNonGDALMDIGeopackage),
                                   pszMetadata,
                                   "GEOPACKAGE" );
            nNonGDALMDIGeopackage ++;
        }
        /*else if( strcmp( pszMDStandardURI, "http://www.isotc211.org/2005/gmd" ) == 0 &&
            strcmp( pszMimeType, "text/xml" ) == 0 )
        {
            char* apszMD[2];
            apszMD[0] = (char*)pszMetadata;
            apszMD[1] = NULL;
            oMDMD.SetMetadata(apszMD, "xml:MD_Metadata");
        }*/
        else
        {
            oMDMD.SetMetadataItem( CPLSPrintf("GPKG_METADATA_ITEM_%d", nNonGDALMDILocal),
                                   pszMetadata );
            nNonGDALMDILocal ++;
        }
    }

    SQLResultFree(&oResult);

    return GDALPamDataset::GetMetadata(pszDomain);
}

/************************************************************************/
/*                            WriteMetadata()                           */
/************************************************************************/

void GDALGeoPackageDataset::WriteMetadata(CPLXMLNode* psXMLNode, /* will be destroyed by the method */
                                          const char* pszTableName)
{
    const bool bIsEmpty = (psXMLNode == nullptr);
    if( !HasMetadataTables() )
    {
        if( bIsEmpty || !CreateMetadataTables() )
        {
            CPLDestroyXMLNode(psXMLNode);
            return;
        }
    }

    char *pszXML = nullptr;
    if( !bIsEmpty )
    {
        CPLXMLNode* psMasterXMLNode = CPLCreateXMLNode( nullptr, CXT_Element,
                                                        "GDALMultiDomainMetadata" );
        psMasterXMLNode->psChild = psXMLNode;
        pszXML = CPLSerializeXMLTree(psMasterXMLNode);
        CPLDestroyXMLNode(psMasterXMLNode);
    }
    // cppcheck-suppress uselessAssignmentPtrArg
    psXMLNode = nullptr;

    char* pszSQL = nullptr;
    if( pszTableName && pszTableName[0] != '\0' )
    {
        pszSQL = sqlite3_mprintf(
            "SELECT md.id FROM gpkg_metadata md "
            "JOIN gpkg_metadata_reference mdr ON (md.id = mdr.md_file_id ) "
            "WHERE md.md_scope = 'dataset' AND md.md_standard_uri='http://gdal.org' "
            "AND md.mime_type='text/xml' AND mdr.reference_scope = 'table' AND lower(mdr.table_name) = lower('%q')",
            pszTableName);
    }
    else
    {
        pszSQL = sqlite3_mprintf(
            "SELECT md.id FROM gpkg_metadata md "
            "JOIN gpkg_metadata_reference mdr ON (md.id = mdr.md_file_id ) "
            "WHERE md.md_scope = 'dataset' AND md.md_standard_uri='http://gdal.org' "
            "AND md.mime_type='text/xml' AND mdr.reference_scope = 'geopackage'");
    }
    OGRErr err;
    int mdId = SQLGetInteger(hDB, pszSQL, &err);
    if( err != OGRERR_NONE )
        mdId = -1;
    sqlite3_free(pszSQL);

    if( bIsEmpty )
    {
        if( mdId >= 0 )
        {
            SQLCommand(hDB,
                       CPLSPrintf("DELETE FROM gpkg_metadata_reference WHERE md_file_id = %d", mdId));
            SQLCommand(hDB,
                       CPLSPrintf("DELETE FROM gpkg_metadata WHERE id = %d", mdId));
        }
    }
    else
    {
        if( mdId >= 0 )
        {
            pszSQL = sqlite3_mprintf(
                "UPDATE gpkg_metadata SET metadata = '%q' WHERE id = %d",
                pszXML, mdId);
        }
        else
        {
            pszSQL = sqlite3_mprintf(
                "INSERT INTO gpkg_metadata (md_scope, md_standard_uri, mime_type, metadata) VALUES "
                "('dataset','http://gdal.org','text/xml','%q')",
                pszXML);
        }
        SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);

        CPLFree(pszXML);

        if( mdId < 0 )
        {
            const sqlite_int64 nFID = sqlite3_last_insert_rowid( hDB );
            if( pszTableName != nullptr && pszTableName[0] != '\0' )
            {
                pszSQL = sqlite3_mprintf(
                    "INSERT INTO gpkg_metadata_reference (reference_scope, table_name, timestamp, md_file_id) VALUES "
                    "('table', '%q', strftime('%%Y-%%m-%%dT%%H:%%M:%%fZ','now'), %d)",
                    pszTableName, (int)nFID);
            }
            else
            {
                pszSQL = sqlite3_mprintf(
                    "INSERT INTO gpkg_metadata_reference (reference_scope, timestamp, md_file_id) VALUES "
                    "('geopackage', strftime('%%Y-%%m-%%dT%%H:%%M:%%fZ','now'), %d)",
                    (int)nFID);
            }
        }
        else
        {
            pszSQL = sqlite3_mprintf(
                "UPDATE gpkg_metadata_reference SET timestamp = strftime('%%Y-%%m-%%dT%%H:%%M:%%fZ','now') WHERE md_file_id = %d",
                mdId);
        }
        SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }
}

/************************************************************************/
/*                        CreateMetadataTables()                        */
/************************************************************************/

bool GDALGeoPackageDataset::CreateMetadataTables()
{
    const bool bCreateTriggers =
        CPLTestBool(CPLGetConfigOption("CREATE_TRIGGERS", "YES"));

    /* From C.10. gpkg_metadata Table 35. gpkg_metadata Table Definition SQL  */
    CPLString osSQL =
        "CREATE TABLE gpkg_metadata ("
        "id INTEGER CONSTRAINT m_pk PRIMARY KEY ASC NOT NULL,"
        "md_scope TEXT NOT NULL DEFAULT 'dataset',"
        "md_standard_uri TEXT NOT NULL,"
        "mime_type TEXT NOT NULL DEFAULT 'text/xml',"
        "metadata TEXT NOT NULL DEFAULT ''"
        ")";

    /* From D.2. metadata Table 40. metadata Trigger Definition SQL  */
    const char* pszMetadataTriggers =
    "CREATE TRIGGER 'gpkg_metadata_md_scope_insert' "
    "BEFORE INSERT ON 'gpkg_metadata' "
    "FOR EACH ROW BEGIN "
    "SELECT RAISE(ABORT, 'insert on table gpkg_metadata violates "
    "constraint: md_scope must be one of undefined | fieldSession | "
    "collectionSession | series | dataset | featureType | feature | "
    "attributeType | attribute | tile | model | catalogue | schema | "
    "taxonomy software | service | collectionHardware | "
    "nonGeographicDataset | dimensionGroup') "
    "WHERE NOT(NEW.md_scope IN "
    "('undefined','fieldSession','collectionSession','series','dataset', "
    "'featureType','feature','attributeType','attribute','tile','model', "
    "'catalogue','schema','taxonomy','software','service', "
    "'collectionHardware','nonGeographicDataset','dimensionGroup')); "
    "END; "
    "CREATE TRIGGER 'gpkg_metadata_md_scope_update' "
    "BEFORE UPDATE OF 'md_scope' ON 'gpkg_metadata' "
    "FOR EACH ROW BEGIN "
    "SELECT RAISE(ABORT, 'update on table gpkg_metadata violates "
    "constraint: md_scope must be one of undefined | fieldSession | "
    "collectionSession | series | dataset | featureType | feature | "
    "attributeType | attribute | tile | model | catalogue | schema | "
    "taxonomy software | service | collectionHardware | "
    "nonGeographicDataset | dimensionGroup') "
    "WHERE NOT(NEW.md_scope IN "
    "('undefined','fieldSession','collectionSession','series','dataset', "
    "'featureType','feature','attributeType','attribute','tile','model', "
    "'catalogue','schema','taxonomy','software','service', "
    "'collectionHardware','nonGeographicDataset','dimensionGroup')); "
    "END";
    if ( bCreateTriggers )
    {
        osSQL += ";";
        osSQL += pszMetadataTriggers;
    }

    /* From C.11. gpkg_metadata_reference Table 36. gpkg_metadata_reference Table Definition SQL */
    osSQL += ";"
        "CREATE TABLE gpkg_metadata_reference ("
        "reference_scope TEXT NOT NULL,"
        "table_name TEXT,"
        "column_name TEXT,"
        "row_id_value INTEGER,"
        "timestamp DATETIME NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now')),"
        "md_file_id INTEGER NOT NULL,"
        "md_parent_id INTEGER,"
        "CONSTRAINT crmr_mfi_fk FOREIGN KEY (md_file_id) REFERENCES gpkg_metadata(id),"
        "CONSTRAINT crmr_mpi_fk FOREIGN KEY (md_parent_id) REFERENCES gpkg_metadata(id)"
        ")";

    /* From D.3. metadata_reference Table 41. gpkg_metadata_reference Trigger Definition SQL   */
    const char* pszMetadataReferenceTriggers =
        "CREATE TRIGGER 'gpkg_metadata_reference_reference_scope_insert' "
        "BEFORE INSERT ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table gpkg_metadata_reference "
        "violates constraint: reference_scope must be one of \"geopackage\", "
        "table\", \"column\", \"row\", \"row/col\"') "
        "WHERE NOT NEW.reference_scope IN "
        "('geopackage','table','column','row','row/col'); "
        "END; "
        "CREATE TRIGGER 'gpkg_metadata_reference_reference_scope_update' "
        "BEFORE UPDATE OF 'reference_scope' ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table gpkg_metadata_reference "
        "violates constraint: reference_scope must be one of \"geopackage\", "
        "\"table\", \"column\", \"row\", \"row/col\"') "
        "WHERE NOT NEW.reference_scope IN "
        "('geopackage','table','column','row','row/col'); "
        "END; "
        "CREATE TRIGGER 'gpkg_metadata_reference_column_name_insert' "
        "BEFORE INSERT ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table gpkg_metadata_reference "
        "violates constraint: column name must be NULL when reference_scope "
        "is \"geopackage\", \"table\" or \"row\"') "
        "WHERE (NEW.reference_scope IN ('geopackage','table','row') "
        "AND NEW.column_name IS NOT NULL); "
        "SELECT RAISE(ABORT, 'insert on table gpkg_metadata_reference "
        "violates constraint: column name must be defined for the specified "
        "table when reference_scope is \"column\" or \"row/col\"') "
        "WHERE (NEW.reference_scope IN ('column','row/col') "
        "AND NOT NEW.table_name IN ( "
        "SELECT name FROM SQLITE_MASTER WHERE type = 'table' "
        "AND name = NEW.table_name "
        "AND sql LIKE ('%' || NEW.column_name || '%'))); "
        "END; "
        "CREATE TRIGGER 'gpkg_metadata_reference_column_name_update' "
        "BEFORE UPDATE OF column_name ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table gpkg_metadata_reference "
        "violates constraint: column name must be NULL when reference_scope "
        "is \"geopackage\", \"table\" or \"row\"') "
        "WHERE (NEW.reference_scope IN ('geopackage','table','row') "
        "AND NEW.column_name IS NOT NULL); "
        "SELECT RAISE(ABORT, 'update on table gpkg_metadata_reference "
        "violates constraint: column name must be defined for the specified "
        "table when reference_scope is \"column\" or \"row/col\"') "
        "WHERE (NEW.reference_scope IN ('column','row/col') "
        "AND NOT NEW.table_name IN ( "
        "SELECT name FROM SQLITE_MASTER WHERE type = 'table' "
        "AND name = NEW.table_name "
        "AND sql LIKE ('%' || NEW.column_name || '%'))); "
        "END; "
        "CREATE TRIGGER 'gpkg_metadata_reference_row_id_value_insert' "
        "BEFORE INSERT ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table gpkg_metadata_reference "
        "violates constraint: row_id_value must be NULL when reference_scope "
        "is \"geopackage\", \"table\" or \"column\"') "
        "WHERE NEW.reference_scope IN ('geopackage','table','column') "
        "AND NEW.row_id_value IS NOT NULL; "
        "END; "
        "CREATE TRIGGER 'gpkg_metadata_reference_row_id_value_update' "
        "BEFORE UPDATE OF 'row_id_value' ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table gpkg_metadata_reference "
        "violates constraint: row_id_value must be NULL when reference_scope "
        "is \"geopackage\", \"table\" or \"column\"') "
        "WHERE NEW.reference_scope IN ('geopackage','table','column') "
        "AND NEW.row_id_value IS NOT NULL; "
        "END; "
        "CREATE TRIGGER 'gpkg_metadata_reference_timestamp_insert' "
        "BEFORE INSERT ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table gpkg_metadata_reference "
        "violates constraint: timestamp must be a valid time in ISO 8601 "
        "\"yyyy-mm-ddThh:mm:ss.cccZ\" form') "
        "WHERE NOT (NEW.timestamp GLOB "
        "'[1-2][0-9][0-9][0-9]-[0-1][0-9]-[0-3][0-9]T[0-2][0-9]:[0-5][0-9]:[0-5][0-9].[0-9][0-9][0-9]Z' "
        "AND strftime('%s',NEW.timestamp) NOT NULL); "
        "END; "
        "CREATE TRIGGER 'gpkg_metadata_reference_timestamp_update' "
        "BEFORE UPDATE OF 'timestamp' ON 'gpkg_metadata_reference' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table gpkg_metadata_reference "
        "violates constraint: timestamp must be a valid time in ISO 8601 "
        "\"yyyy-mm-ddThh:mm:ss.cccZ\" form') "
        "WHERE NOT (NEW.timestamp GLOB "
        "'[1-2][0-9][0-9][0-9]-[0-1][0-9]-[0-3][0-9]T[0-2][0-9]:[0-5][0-9]:[0-5][0-9].[0-9][0-9][0-9]Z' "
        "AND strftime('%s',NEW.timestamp) NOT NULL); "
        "END";
    if ( bCreateTriggers )
    {
        osSQL += ";";
        osSQL += pszMetadataReferenceTriggers;
    }

    if( CreateExtensionsTableIfNecessary() != OGRERR_NONE )
        return false;

    osSQL += ";";
    osSQL +=
        "INSERT INTO gpkg_extensions "
        "(table_name, column_name, extension_name, definition, scope) "
        "VALUES "
        "('gpkg_metadata', NULL, 'gpkg_metadata', 'http://www.geopackage.org/spec120/#extension_metadata', 'read-write')";

    osSQL += ";";
    osSQL +=
        "INSERT INTO gpkg_extensions "
        "(table_name, column_name, extension_name, definition, scope) "
        "VALUES "
        "('gpkg_metadata_reference', NULL, 'gpkg_metadata', 'http://www.geopackage.org/spec120/#extension_metadata', 'read-write')";

    return SQLCommand(hDB, osSQL) == OGRERR_NONE;
}

/************************************************************************/
/*                            FlushMetadata()                           */
/************************************************************************/

CPLErr GDALGeoPackageDataset::FlushMetadata()
{
    if( !m_bMetadataDirty || m_poParentDS != nullptr ||
        !CPLTestBool(CPLGetConfigOption("CREATE_METADATA_TABLES", "YES")) )
        return CE_None;
    m_bMetadataDirty = false;

    bool bCanWriteAreaOrPoint = !m_bGridCellEncodingAsCO &&
                (m_eTF == GPKG_TF_PNG_16BIT ||
                 m_eTF == GPKG_TF_TIFF_32BIT_FLOAT);
    if( !m_osRasterTable.empty() )
    {
        const char* pszIdentifier = GDALGeoPackageDataset::GetMetadataItem("IDENTIFIER");
        const char* pszDescription = GDALGeoPackageDataset::GetMetadataItem("DESCRIPTION");
        if( !m_bIdentifierAsCO && pszIdentifier != nullptr &&
            pszIdentifier != m_osIdentifier )
        {
            m_osIdentifier = pszIdentifier;
            char* pszSQL = sqlite3_mprintf(
                "UPDATE gpkg_contents SET identifier = '%q' WHERE lower(table_name) = lower('%q')",
                pszIdentifier, m_osRasterTable.c_str());
            SQLCommand(hDB, pszSQL);
            sqlite3_free(pszSQL);
        }
        if( !m_bDescriptionAsCO && pszDescription != nullptr &&
            pszDescription != m_osDescription )
        {
            m_osDescription = pszDescription;
            char* pszSQL = sqlite3_mprintf(
                "UPDATE gpkg_contents SET description = '%q' WHERE lower(table_name) = lower('%q')",
                pszDescription, m_osRasterTable.c_str());
            SQLCommand(hDB, pszSQL);
            sqlite3_free(pszSQL);
        }
        if( bCanWriteAreaOrPoint )
        {
            const char* pszAreaOrPoint = GDALGeoPackageDataset::GetMetadataItem(GDALMD_AREA_OR_POINT);
            if( pszAreaOrPoint && EQUAL(pszAreaOrPoint, GDALMD_AOP_AREA) )
            {
                bCanWriteAreaOrPoint = false;
                char* pszSQL = sqlite3_mprintf(
                    "UPDATE gpkg_2d_gridded_coverage_ancillary SET "
                    "grid_cell_encoding = 'grid-value-is-area' WHERE "
                    "lower(tile_matrix_set_name) = lower('%q')",
                    m_osRasterTable.c_str());
                SQLCommand(hDB, pszSQL);
                sqlite3_free(pszSQL);
            }
            else if( pszAreaOrPoint && EQUAL(pszAreaOrPoint, GDALMD_AOP_POINT) )
            {
                bCanWriteAreaOrPoint = false;
                char* pszSQL = sqlite3_mprintf(
                    "UPDATE gpkg_2d_gridded_coverage_ancillary SET "
                    "grid_cell_encoding = 'grid-value-is-center' WHERE "
                    "lower(tile_matrix_set_name) = lower('%q')",
                    m_osRasterTable.c_str());
                SQLCommand(hDB, pszSQL);
                sqlite3_free(pszSQL);
            }
        }
    }

    char** papszMDDup = nullptr;
    for( char** papszIter = GDALGeoPackageDataset::GetMetadata(); papszIter && *papszIter; ++papszIter )
    {
        if( STARTS_WITH_CI(*papszIter, "IDENTIFIER=") )
            continue;
        if( STARTS_WITH_CI(*papszIter, "DESCRIPTION=") )
            continue;
        if( STARTS_WITH_CI(*papszIter, "ZOOM_LEVEL=") )
            continue;
        if( STARTS_WITH_CI(*papszIter, "GPKG_METADATA_ITEM_") )
            continue;
        if( (m_eTF == GPKG_TF_PNG_16BIT ||
             m_eTF == GPKG_TF_TIFF_32BIT_FLOAT) &&
             !bCanWriteAreaOrPoint &&
            STARTS_WITH_CI(*papszIter, GDALMD_AREA_OR_POINT) )
        {
            continue;
        }
        papszMDDup = CSLInsertString(papszMDDup, -1, *papszIter);
    }

    CPLXMLNode* psXMLNode = nullptr;
    {
        GDALMultiDomainMetadata oLocalMDMD;
        char** papszDomainList = oMDMD.GetDomainList();
        char** papszIter = papszDomainList;
        oLocalMDMD.SetMetadata(papszMDDup);
        while( papszIter && *papszIter )
        {
            if( !EQUAL(*papszIter, "") &&
                !EQUAL(*papszIter, "IMAGE_STRUCTURE") &&
                !EQUAL(*papszIter, "GEOPACKAGE") )
                oLocalMDMD.SetMetadata(oMDMD.GetMetadata(*papszIter), *papszIter);
            papszIter ++;
        }
        psXMLNode = oLocalMDMD.Serialize();
    }

    CSLDestroy(papszMDDup);
    papszMDDup = nullptr;

    WriteMetadata(psXMLNode, m_osRasterTable.c_str() );

    if( !m_osRasterTable.empty() )
    {
        char** papszGeopackageMD = GDALGeoPackageDataset::GetMetadata("GEOPACKAGE");

        papszMDDup = nullptr;
        for( char** papszIter = papszGeopackageMD; papszIter && *papszIter; ++papszIter )
        {
            papszMDDup = CSLInsertString(papszMDDup, -1, *papszIter);
        }

        GDALMultiDomainMetadata oLocalMDMD;
        oLocalMDMD.SetMetadata(papszMDDup);
        CSLDestroy(papszMDDup);
        papszMDDup = nullptr;
        psXMLNode = oLocalMDMD.Serialize();

        WriteMetadata(psXMLNode, nullptr);
    }

    for(int i=0;i<m_nLayers;i++)
    {
        const char* pszIdentifier = m_papoLayers[i]->GetMetadataItem("IDENTIFIER");
        const char* pszDescription = m_papoLayers[i]->GetMetadataItem("DESCRIPTION");
        if( pszIdentifier != nullptr )
        {
            char* pszSQL = sqlite3_mprintf(
                "UPDATE gpkg_contents SET identifier = '%q' WHERE lower(table_name) = lower('%q')",
                pszIdentifier, m_papoLayers[i]->GetName());
            SQLCommand(hDB, pszSQL);
            sqlite3_free(pszSQL);
        }
        if( pszDescription != nullptr )
        {
            char* pszSQL = sqlite3_mprintf(
                "UPDATE gpkg_contents SET description = '%q' WHERE lower(table_name) = lower('%q')",
                pszDescription, m_papoLayers[i]->GetName());
            SQLCommand(hDB, pszSQL);
            sqlite3_free(pszSQL);
        }

        papszMDDup = nullptr;
        for( char** papszIter = m_papoLayers[i]->GetMetadata(); papszIter && *papszIter; ++papszIter )
        {
            if( STARTS_WITH_CI(*papszIter, "IDENTIFIER=") )
                continue;
            if( STARTS_WITH_CI(*papszIter, "DESCRIPTION=") )
                continue;
            if( STARTS_WITH_CI(*papszIter, "OLMD_FID64=") )
                continue;
            papszMDDup = CSLInsertString(papszMDDup, -1, *papszIter);
        }

        {
            GDALMultiDomainMetadata oLocalMDMD;
            char** papszDomainList = m_papoLayers[i]->GetMetadataDomainList();
            char** papszIter = papszDomainList;
            oLocalMDMD.SetMetadata(papszMDDup);
            while( papszIter && *papszIter )
            {
                if( !EQUAL(*papszIter, "") )
                    oLocalMDMD.SetMetadata(m_papoLayers[i]->GetMetadata(*papszIter), *papszIter);
                papszIter ++;
            }
            CSLDestroy(papszDomainList);
            psXMLNode = oLocalMDMD.Serialize();
        }

        CSLDestroy(papszMDDup);
        papszMDDup = nullptr;

        WriteMetadata(psXMLNode, m_papoLayers[i]->GetName() );
    }

    return CE_None;
}

/************************************************************************/
/*                          GetMetadataItem()                           */
/************************************************************************/

const char *GDALGeoPackageDataset::GetMetadataItem( const char * pszName,
                                                    const char * pszDomain )
{
    pszDomain = CheckMetadataDomain(pszDomain);
    return CSLFetchNameValue( GetMetadata(pszDomain), pszName );
}

/************************************************************************/
/*                            SetMetadata()                             */
/************************************************************************/

CPLErr GDALGeoPackageDataset::SetMetadata( char ** papszMetadata, const char * pszDomain )
{
    pszDomain = CheckMetadataDomain(pszDomain);
    m_bMetadataDirty = true;
    GetMetadata(); /* force loading from storage if needed */
    return GDALPamDataset::SetMetadata(papszMetadata, pszDomain);
}

/************************************************************************/
/*                          SetMetadataItem()                           */
/************************************************************************/

CPLErr GDALGeoPackageDataset::SetMetadataItem( const char * pszName,
                                               const char * pszValue,
                                               const char * pszDomain )
{
    pszDomain = CheckMetadataDomain(pszDomain);
    m_bMetadataDirty = true;
    GetMetadata(); /* force loading from storage if needed */
    return GDALPamDataset::SetMetadataItem(pszName, pszValue, pszDomain);
}

/************************************************************************/
/*                                Create()                              */
/************************************************************************/

int GDALGeoPackageDataset::Create( const char * pszFilename,
                                   int nXSize,
                                   int nYSize,
                                   int nBandsIn,
                                   GDALDataType eDT,
                                   char **papszOptions )
{
    CPLString osCommand;

    /* First, ensure there isn't any such file yet. */
    VSIStatBufL sStatBuf;

    if( nBandsIn != 0 )
    {
        if( eDT == GDT_Byte )
        {
            if( nBandsIn != 1 && nBandsIn != 2 && nBandsIn != 3 && nBandsIn != 4 )
            {
                CPLError(CE_Failure, CPLE_NotSupported,
                        "Only 1 (Grey/ColorTable), 2 (Grey+Alpha), "
                        "3 (RGB) or 4 (RGBA) band dataset supported for "
                        "Byte datatype");
                return FALSE;
            }
        }
        else if( eDT == GDT_Int16 || eDT == GDT_UInt16 || eDT == GDT_Float32 )
        {
            if( nBandsIn != 1 )
            {
                CPLError(CE_Failure, CPLE_NotSupported,
                        "Only single band dataset supported for non Byte "
                        "datatype");
                return FALSE;
            }
        }
        else
        {
            CPLError(CE_Failure, CPLE_NotSupported,
                     "Only Byte, Int16, UInt16 or Float32 supported");
            return FALSE;
        }

    }

    bool bFileExists = false;
    if( VSIStatL( pszFilename, &sStatBuf ) == 0 )
    {
        bFileExists = true;
        if( nBandsIn == 0 ||
            !CPLTestBool(CSLFetchNameValueDef(papszOptions, "APPEND_SUBDATASET", "NO")) )
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                    "A file system object called '%s' already exists.",
                    pszFilename );

            return FALSE;
        }
    }
    m_pszFilename = CPLStrdup(pszFilename);
    m_bNew = true;
    bUpdate = TRUE;
    eAccess = GA_Update; /* hum annoying duplication */

    // for test/debug purposes only. true is the nominal value
    m_bPNGSupports2Bands = CPLTestBool(CPLGetConfigOption("GPKG_PNG_SUPPORTS_2BANDS", "TRUE"));
    m_bPNGSupportsCT = CPLTestBool(CPLGetConfigOption("GPKG_PNG_SUPPORTS_CT", "TRUE"));

    if( !OpenOrCreateDB(bFileExists
                        ? SQLITE_OPEN_READWRITE
                        : SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE) )
        return FALSE;

    /* Default to synchronous=off for performance for new file */
    if( !bFileExists &&
        CPLGetConfigOption("OGR_SQLITE_SYNCHRONOUS", nullptr) == nullptr )
    {
        SQLCommand( hDB, "PRAGMA synchronous = OFF" );
    }

    /* OGR UTF-8 support. If we set the UTF-8 Pragma early on, it */
    /* will be written into the main file and supported henceforth */
    SQLCommand(hDB, "PRAGMA encoding = \"UTF-8\"");

    if( bFileExists )
    {
        VSILFILE* fp = VSIFOpenL(pszFilename, "rb");
        if( fp )
        {
            GByte abyHeader[100];
            VSIFReadL(abyHeader, 1, sizeof(abyHeader), fp);
            VSIFCloseL(fp);

            memcpy(&m_nApplicationId, abyHeader + knApplicationIdPos, 4);
            m_nApplicationId = CPL_MSBWORD32(m_nApplicationId);
            memcpy(&m_nUserVersion, abyHeader + knUserVersionPos, 4);
            m_nUserVersion = CPL_MSBWORD32(m_nUserVersion);

            if( m_nApplicationId == GP10_APPLICATION_ID )
            {
                CPLDebug("GPKG", "GeoPackage v1.0");
            }
            else if( m_nApplicationId == GP11_APPLICATION_ID )
            {
                CPLDebug("GPKG", "GeoPackage v1.1");
            }
            else if( m_nApplicationId == GPKG_APPLICATION_ID &&
                    m_nUserVersion >= GPKG_1_2_VERSION )
            {
                CPLDebug("GPKG", "GeoPackage v%d.%d.%d",
                        m_nUserVersion / 10000,
                        (m_nUserVersion % 10000) / 100,
                        m_nUserVersion % 100);
            }
        }

        // Detect definition_12_063 column
        {
            sqlite3_stmt* hSQLStmt = nullptr;
            int rc = sqlite3_prepare_v2( hDB,
                "SELECT definition_12_063 FROM gpkg_spatial_ref_sys ", -1,
                &hSQLStmt, nullptr );
            if( rc == SQLITE_OK )
            {
                m_bHasDefinition12_063 = true;
                sqlite3_finalize(hSQLStmt);
            }
        }
    }

    const char* pszVersion = CSLFetchNameValue(papszOptions, "VERSION");
    if( pszVersion && !EQUAL(pszVersion, "AUTO") )
    {
        if( EQUAL(pszVersion, "1.0") )
        {
            m_nApplicationId = GP10_APPLICATION_ID;
            m_nUserVersion = 0;
        }
        else if( EQUAL(pszVersion, "1.1") )
        {
            m_nApplicationId = GP11_APPLICATION_ID;
            m_nUserVersion = 0;
        }
        else if( EQUAL(pszVersion, "1.2") )
        {
            m_nApplicationId = GPKG_APPLICATION_ID;
            m_nUserVersion = GPKG_1_2_VERSION;
        }
    }

    SoftStartTransaction();

    CPLString osSQL;
    if( !bFileExists )
    {
        /* Requirement 10: A GeoPackage SHALL include a gpkg_spatial_ref_sys table */
        /* http://opengis.github.io/geopackage/#spatial_ref_sys */
        osSQL =
            "CREATE TABLE gpkg_spatial_ref_sys ("
            "srs_name TEXT NOT NULL,"
            "srs_id INTEGER NOT NULL PRIMARY KEY,"
            "organization TEXT NOT NULL,"
            "organization_coordsys_id INTEGER NOT NULL,"
            "definition  TEXT NOT NULL,"
            "description TEXT";
        if( CPLTestBool(CPLGetConfigOption("GPKG_ADD_DEFINITION_12_063", "NO")) )
        {
            m_bHasDefinition12_063 = true;
            osSQL += ", definition_12_063 TEXT NOT NULL";
        }
        osSQL += 
            ")"
            ";"
        /* Requirement 11: The gpkg_spatial_ref_sys table in a GeoPackage SHALL */
        /* contain a record for EPSG:4326, the geodetic WGS84 SRS */
        /* http://opengis.github.io/geopackage/#spatial_ref_sys */

            "INSERT INTO gpkg_spatial_ref_sys ("
            "srs_name, srs_id, organization, organization_coordsys_id, definition, description";
        if( m_bHasDefinition12_063 )
            osSQL += ", definition_12_063";
        osSQL +=
            ") VALUES ("
            "'WGS 84 geodetic', 4326, 'EPSG', 4326, '"
            "GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.0174532925199433,AUTHORITY[\"EPSG\",\"9122\"]],AXIS[\"Latitude\",NORTH],AXIS[\"Longitude\",EAST],AUTHORITY[\"EPSG\",\"4326\"]]"
            "', 'longitude/latitude coordinates in decimal degrees on the WGS 84 spheroid'";
        if( m_bHasDefinition12_063 )
            osSQL += ", 'GEODCRS[\"WGS 84\", DATUM[\"World Geodetic System 1984\", ELLIPSOID[\"WGS 84\",6378137, 298.257223563, LENGTHUNIT[\"metre\", 1.0]]], PRIMEM[\"Greenwich\", 0.0, ANGLEUNIT[\"degree\",0.0174532925199433]], CS[ellipsoidal, 2], AXIS[\"latitude\", north, ORDER[1]], AXIS[\"longitude\", east, ORDER[2]], ANGLEUNIT[\"degree\", 0.0174532925199433], ID[\"EPSG\", 4326]]'";
        osSQL +=
            ")"
            ";"
        /* Requirement 11: The gpkg_spatial_ref_sys table in a GeoPackage SHALL */
        /* contain a record with an srs_id of -1, an organization of “NONE”, */
        /* an organization_coordsys_id of -1, and definition “undefined” */
        /* for undefined Cartesian coordinate reference systems */
        /* http://opengis.github.io/geopackage/#spatial_ref_sys */
            "INSERT INTO gpkg_spatial_ref_sys ("
            "srs_name, srs_id, organization, organization_coordsys_id, definition, description";
        if( m_bHasDefinition12_063 )
            osSQL += ", definition_12_063";
        osSQL +=
            ") VALUES ("
            "'Undefined cartesian SRS', -1, 'NONE', -1, 'undefined', 'undefined cartesian coordinate reference system'";
        if( m_bHasDefinition12_063 )
            osSQL += ", 'undefined'";
        osSQL +=
            ")"
            ";"
        /* Requirement 11: The gpkg_spatial_ref_sys table in a GeoPackage SHALL */
        /* contain a record with an srs_id of 0, an organization of “NONE”, */
        /* an organization_coordsys_id of 0, and definition “undefined” */
        /* for undefined geographic coordinate reference systems */
        /* http://opengis.github.io/geopackage/#spatial_ref_sys */
            "INSERT INTO gpkg_spatial_ref_sys ("
            "srs_name, srs_id, organization, organization_coordsys_id, definition, description";
        if( m_bHasDefinition12_063 )
            osSQL += ", definition_12_063";
        osSQL +=
            ") VALUES ("
            "'Undefined geographic SRS', 0, 'NONE', 0, 'undefined', 'undefined geographic coordinate reference system'";
        if( m_bHasDefinition12_063 )
            osSQL += ", 'undefined'";
        osSQL +=
            ")"
            ";"
        /* Requirement 13: A GeoPackage file SHALL include a gpkg_contents table */
        /* http://opengis.github.io/geopackage/#_contents */
            "CREATE TABLE gpkg_contents ("
            "table_name TEXT NOT NULL PRIMARY KEY,"
            "data_type TEXT NOT NULL,"
            "identifier TEXT UNIQUE,"
            "description TEXT DEFAULT '',"
            "last_change DATETIME NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now')),"
            "min_x DOUBLE, min_y DOUBLE,"
            "max_x DOUBLE, max_y DOUBLE,"
            "srs_id INTEGER,"
            "CONSTRAINT fk_gc_r_srs_id FOREIGN KEY (srs_id) REFERENCES gpkg_spatial_ref_sys(srs_id)"
            ")"
            ;

#ifdef ENABLE_GPKG_OGR_CONTENTS
        if( CPLFetchBool(papszOptions, "ADD_GPKG_OGR_CONTENTS", true) )
        {
            m_bHasGPKGOGRContents = true;
            osSQL += 
                ";"
                "CREATE TABLE gpkg_ogr_contents("
                "table_name TEXT NOT NULL PRIMARY KEY,"
                "feature_count INTEGER DEFAULT NULL"
                ")";
        }
#endif

        /* Requirement 21: A GeoPackage with a gpkg_contents table row with a “features” */
        /* data_type SHALL contain a gpkg_geometry_columns table or updateable view */
        /* http://opengis.github.io/geopackage/#_geometry_columns */
        const bool bCreateGeometryColumns =
            CPLTestBool(CPLGetConfigOption("CREATE_GEOMETRY_COLUMNS", "YES"));
        if( bCreateGeometryColumns )
        {
            m_bHasGPKGGeometryColumns = true;
            osSQL += ";";
            osSQL += pszCREATE_GPKG_GEOMETRY_COLUMNS;
        }
    }

    const bool bCreateTriggers =
        CPLTestBool(CPLGetConfigOption("CREATE_TRIGGERS", "YES"));
    if( (bFileExists && nBandsIn != 0 && SQLGetInteger(hDB,
            "SELECT 1 FROM sqlite_master WHERE name = 'gpkg_tile_matrix_set' "
            "AND type in ('table', 'view')", nullptr) == 0 ) ||
        (!bFileExists &&
         CPLTestBool(CPLGetConfigOption("CREATE_RASTER_TABLES", "YES"))) )
    {
        if( !osSQL.empty() )
            osSQL += ";";

        /* From C.5. gpkg_tile_matrix_set Table 28. gpkg_tile_matrix_set Table Creation SQL  */
        osSQL +=
            "CREATE TABLE gpkg_tile_matrix_set ("
            "table_name TEXT NOT NULL PRIMARY KEY,"
            "srs_id INTEGER NOT NULL,"
            "min_x DOUBLE NOT NULL,"
            "min_y DOUBLE NOT NULL,"
            "max_x DOUBLE NOT NULL,"
            "max_y DOUBLE NOT NULL,"
            "CONSTRAINT fk_gtms_table_name FOREIGN KEY (table_name) REFERENCES gpkg_contents(table_name),"
            "CONSTRAINT fk_gtms_srs FOREIGN KEY (srs_id) REFERENCES gpkg_spatial_ref_sys (srs_id)"
            ")"
            ";"

        /* From C.6. gpkg_tile_matrix Table 29. gpkg_tile_matrix Table Creation SQL */
            "CREATE TABLE gpkg_tile_matrix ("
            "table_name TEXT NOT NULL,"
            "zoom_level INTEGER NOT NULL,"
            "matrix_width INTEGER NOT NULL,"
            "matrix_height INTEGER NOT NULL,"
            "tile_width INTEGER NOT NULL,"
            "tile_height INTEGER NOT NULL,"
            "pixel_x_size DOUBLE NOT NULL,"
            "pixel_y_size DOUBLE NOT NULL,"
            "CONSTRAINT pk_ttm PRIMARY KEY (table_name, zoom_level),"
            "CONSTRAINT fk_tmm_table_name FOREIGN KEY (table_name) REFERENCES gpkg_contents(table_name)"
            ")";

        if( bCreateTriggers )
        {
        /* From D.1. gpkg_tile_matrix Table 39. gpkg_tile_matrix Trigger Definition SQL */
        const char* pszTileMatrixTrigger =
        "CREATE TRIGGER 'gpkg_tile_matrix_zoom_level_insert' "
        "BEFORE INSERT ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''gpkg_tile_matrix'' violates constraint: zoom_level cannot be less than 0') "
        "WHERE (NEW.zoom_level < 0); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_zoom_level_update' "
        "BEFORE UPDATE of zoom_level ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''gpkg_tile_matrix'' violates constraint: zoom_level cannot be less than 0') "
        "WHERE (NEW.zoom_level < 0); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_matrix_width_insert' "
        "BEFORE INSERT ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''gpkg_tile_matrix'' violates constraint: matrix_width cannot be less than 1') "
        "WHERE (NEW.matrix_width < 1); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_matrix_width_update' "
        "BEFORE UPDATE OF matrix_width ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''gpkg_tile_matrix'' violates constraint: matrix_width cannot be less than 1') "
        "WHERE (NEW.matrix_width < 1); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_matrix_height_insert' "
        "BEFORE INSERT ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''gpkg_tile_matrix'' violates constraint: matrix_height cannot be less than 1') "
        "WHERE (NEW.matrix_height < 1); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_matrix_height_update' "
        "BEFORE UPDATE OF matrix_height ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''gpkg_tile_matrix'' violates constraint: matrix_height cannot be less than 1') "
        "WHERE (NEW.matrix_height < 1); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_pixel_x_size_insert' "
        "BEFORE INSERT ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''gpkg_tile_matrix'' violates constraint: pixel_x_size must be greater than 0') "
        "WHERE NOT (NEW.pixel_x_size > 0); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_pixel_x_size_update' "
        "BEFORE UPDATE OF pixel_x_size ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''gpkg_tile_matrix'' violates constraint: pixel_x_size must be greater than 0') "
        "WHERE NOT (NEW.pixel_x_size > 0); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_pixel_y_size_insert' "
        "BEFORE INSERT ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''gpkg_tile_matrix'' violates constraint: pixel_y_size must be greater than 0') "
        "WHERE NOT (NEW.pixel_y_size > 0); "
        "END; "
        "CREATE TRIGGER 'gpkg_tile_matrix_pixel_y_size_update' "
        "BEFORE UPDATE OF pixel_y_size ON 'gpkg_tile_matrix' "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''gpkg_tile_matrix'' violates constraint: pixel_y_size must be greater than 0') "
        "WHERE NOT (NEW.pixel_y_size > 0); "
        "END;";
            osSQL += ";";
            osSQL += pszTileMatrixTrigger;
        }
    }

    if ( !osSQL.empty() && OGRERR_NONE != SQLCommand(hDB, osSQL) )
        return FALSE;

    if( !bFileExists )
    {
        if( CPLTestBool(CPLGetConfigOption("CREATE_METADATA_TABLES", "NO")) &&
            !CreateMetadataTables() )
            return FALSE;

        if( m_bHasDefinition12_063 )
        {
            if( OGRERR_NONE != CreateExtensionsTableIfNecessary() ||
                OGRERR_NONE != SQLCommand(hDB,
                "INSERT INTO gpkg_extensions "
                "(table_name, column_name, extension_name, definition, scope) "
                "VALUES "
                "('gpkg_spatial_ref_sys', 'definition_12_063', 'gpkg_crs_wkt', 'http://www.geopackage.org/spec120/#extension_crs_wkt', 'read-write')") )
            {
                return FALSE;
            }
        }
    }

    if( nBandsIn != 0 )
    {
        const char* pszTableName = CPLGetBasename(m_pszFilename);
        m_osRasterTable = CSLFetchNameValueDef(papszOptions, "RASTER_TABLE", pszTableName);
        if( m_osRasterTable.empty() )
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "RASTER_TABLE must be set to a non empty value");
            return FALSE;
        }
        m_bIdentifierAsCO = CSLFetchNameValue(papszOptions, "RASTER_IDENTIFIER" ) != nullptr;
        m_osIdentifier = CSLFetchNameValueDef(papszOptions, "RASTER_IDENTIFIER", m_osRasterTable);
        m_bDescriptionAsCO = CSLFetchNameValue(papszOptions, "RASTER_DESCRIPTION" ) != nullptr;
        m_osDescription = CSLFetchNameValueDef(papszOptions, "RASTER_DESCRIPTION", "");
        SetDataType(eDT);
        if( eDT == GDT_Int16 )
            SetGlobalOffsetScale(-32768.0, 1.0);

        /* From C.7. sample_tile_pyramid (Informative) Table 31. EXAMPLE: tiles table Create Table SQL (Informative) */
        char* pszSQL = sqlite3_mprintf("CREATE TABLE \"%w\" ("
          "id INTEGER PRIMARY KEY AUTOINCREMENT,"
          "zoom_level INTEGER NOT NULL,"
          "tile_column INTEGER NOT NULL,"
          "tile_row INTEGER NOT NULL,"
          "tile_data BLOB NOT NULL,"
          "UNIQUE (zoom_level, tile_column, tile_row)"
        ")", m_osRasterTable.c_str());
        osSQL = pszSQL;
        sqlite3_free(pszSQL);

        if( bCreateTriggers )
        {
        /* From D.5. sample_tile_pyramid Table 43. tiles table Trigger Definition SQL  */
        pszSQL = sqlite3_mprintf("CREATE TRIGGER \"%w_zoom_insert\" "
        "BEFORE INSERT ON \"%w\" "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''%q'' violates constraint: zoom_level not specified for table in gpkg_tile_matrix') "
        "WHERE NOT (NEW.zoom_level IN (SELECT zoom_level FROM gpkg_tile_matrix WHERE lower(table_name) = lower('%q'))) ; "
        "END; "
        "CREATE TRIGGER \"%w_zoom_update\" "
        "BEFORE UPDATE OF zoom_level ON \"%w\" "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''%q'' violates constraint: zoom_level not specified for table in gpkg_tile_matrix') "
        "WHERE NOT (NEW.zoom_level IN (SELECT zoom_level FROM gpkg_tile_matrix WHERE lower(table_name) = lower('%q'))) ; "
        "END; "
        "CREATE TRIGGER \"%w_tile_column_insert\" "
        "BEFORE INSERT ON \"%w\" "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''%q'' violates constraint: tile_column cannot be < 0') "
        "WHERE (NEW.tile_column < 0) ; "
        "SELECT RAISE(ABORT, 'insert on table ''%q'' violates constraint: tile_column must by < matrix_width specified for table and zoom level in gpkg_tile_matrix') "
        "WHERE NOT (NEW.tile_column < (SELECT matrix_width FROM gpkg_tile_matrix WHERE lower(table_name) = lower('%q') AND zoom_level = NEW.zoom_level)); "
        "END; "
        "CREATE TRIGGER \"%w_tile_column_update\" "
        "BEFORE UPDATE OF tile_column ON \"%w\" "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''%q'' violates constraint: tile_column cannot be < 0') "
        "WHERE (NEW.tile_column < 0) ; "
        "SELECT RAISE(ABORT, 'update on table ''%q'' violates constraint: tile_column must by < matrix_width specified for table and zoom level in gpkg_tile_matrix') "
        "WHERE NOT (NEW.tile_column < (SELECT matrix_width FROM gpkg_tile_matrix WHERE lower(table_name) = lower('%q') AND zoom_level = NEW.zoom_level)); "
        "END; "
        "CREATE TRIGGER \"%w_tile_row_insert\" "
        "BEFORE INSERT ON \"%w\" "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'insert on table ''%q'' violates constraint: tile_row cannot be < 0') "
        "WHERE (NEW.tile_row < 0) ; "
        "SELECT RAISE(ABORT, 'insert on table ''%q'' violates constraint: tile_row must by < matrix_height specified for table and zoom level in gpkg_tile_matrix') "
        "WHERE NOT (NEW.tile_row < (SELECT matrix_height FROM gpkg_tile_matrix WHERE lower(table_name) = lower('%q') AND zoom_level = NEW.zoom_level)); "
        "END; "
        "CREATE TRIGGER \"%w_tile_row_update\" "
        "BEFORE UPDATE OF tile_row ON \"%w\" "
        "FOR EACH ROW BEGIN "
        "SELECT RAISE(ABORT, 'update on table ''%q'' violates constraint: tile_row cannot be < 0') "
        "WHERE (NEW.tile_row < 0) ; "
        "SELECT RAISE(ABORT, 'update on table ''%q'' violates constraint: tile_row must by < matrix_height specified for table and zoom level in gpkg_tile_matrix') "
        "WHERE NOT (NEW.tile_row < (SELECT matrix_height FROM gpkg_tile_matrix WHERE lower(table_name) = lower('%q') AND zoom_level = NEW.zoom_level)); "
        "END; ",
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str(),
        m_osRasterTable.c_str()
        );

            osSQL += ";";
            osSQL += pszSQL;
            sqlite3_free(pszSQL);
        }

        OGRErr eErr = SQLCommand(hDB, osSQL);
        if ( OGRERR_NONE != eErr )
            return FALSE;

        const char* pszTF = CSLFetchNameValue(papszOptions, "TILE_FORMAT");
        if( eDT == GDT_Int16 || eDT == GDT_UInt16 )
        {
            m_eTF = GPKG_TF_PNG_16BIT;
            if( pszTF )
            {
                if( !EQUAL(pszTF, "AUTO") && !EQUAL(pszTF, "PNG") )
                {
                    CPLError(CE_Warning, CPLE_NotSupported,
                             "Only AUTO or PNG supported "
                             "as tile format for Int16 / UInt16");
                }
            }
        }
        else if( eDT == GDT_Float32 )
        {
            m_eTF = GPKG_TF_TIFF_32BIT_FLOAT;
            if( pszTF )
            {
                if( EQUAL(pszTF, "PNG") )
                    m_eTF = GPKG_TF_PNG_16BIT;
                else if( !EQUAL(pszTF, "AUTO") && !EQUAL(pszTF, "TIFF") )
                {
                    CPLError(CE_Warning, CPLE_NotSupported,
                             "Only AUTO, PNG or TIFF supported "
                             "as tile format for Float32");
                }
            }
        }
        else
        {
            if( pszTF )
                m_eTF = GDALGPKGMBTilesGetTileFormat(pszTF);
        }

        if( eDT != GDT_Byte )
        {
            if( !CreateTileGriddedTable(papszOptions) )
                return FALSE;
        }

        nRasterXSize = nXSize;
        nRasterYSize = nYSize;

        const char* pszTileSize = CSLFetchNameValueDef(papszOptions, "BLOCKSIZE", "256");
        const char* pszTileWidth = CSLFetchNameValueDef(papszOptions, "BLOCKXSIZE", pszTileSize);
        const char* pszTileHeight = CSLFetchNameValueDef(papszOptions, "BLOCKYSIZE", pszTileSize);
        int nTileWidth = atoi(pszTileWidth);
        int nTileHeight = atoi(pszTileHeight);
        if( (nTileWidth < 8 || nTileWidth > 4096 || nTileHeight < 8 || nTileHeight > 4096) &&
            !CPLTestBool(CPLGetConfigOption("GPKG_ALLOW_CRAZY_SETTINGS", "NO")) )
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Invalid block dimensions: %dx%d",
                     nTileWidth, nTileHeight);
            return FALSE;
        }

        for(int i = 1; i <= nBandsIn; i ++)
            SetBand( i, new GDALGeoPackageRasterBand(this, nTileWidth, nTileHeight) );

        GDALPamDataset::SetMetadataItem("INTERLEAVE", "PIXEL", "IMAGE_STRUCTURE");
        GDALPamDataset::SetMetadataItem("IDENTIFIER", m_osIdentifier);
        if( !m_osDescription.empty() )
            GDALPamDataset::SetMetadataItem("DESCRIPTION", m_osDescription);

        ParseCompressionOptions(papszOptions);

        if( m_eTF == GPKG_TF_WEBP )
        {
            if( !RegisterWebPExtension() )
                return FALSE;
        }

        const char* pszTilingScheme = CSLFetchNameValue(papszOptions, "TILING_SCHEME");
        if( pszTilingScheme )
        {
            m_osTilingScheme = pszTilingScheme;
            bool bFound = false;
            for(size_t iScheme = 0;
                iScheme < sizeof(asTilingShemes)/sizeof(asTilingShemes[0]);
                 iScheme++ )
            {
                if( EQUAL(m_osTilingScheme, asTilingShemes[iScheme].pszName) )
                {
                    if( nTileWidth != asTilingShemes[iScheme].nTileWidth ||
                        nTileHeight != asTilingShemes[iScheme].nTileHeight )
                    {
                        CPLError(CE_Failure, CPLE_NotSupported,
                                "Tile dimension should be %dx%d for %s tiling scheme",
                                asTilingShemes[iScheme].nTileWidth,
                                asTilingShemes[iScheme].nTileHeight,
                                m_osTilingScheme.c_str());
                        return FALSE;
                    }

                    // Implicitly sets SRS.
                    OGRSpatialReference oSRS;
                    if( oSRS.importFromEPSG(asTilingShemes[iScheme].nEPSGCode)
                        != OGRERR_NONE )
                        return FALSE;
                    char* pszWKT = nullptr;
                    oSRS.exportToWkt(&pszWKT);
                    SetProjection(pszWKT);
                    CPLFree(pszWKT);

                    bFound = true;
                    break;
                }
            }
            if( !bFound )
                m_osTilingScheme = "CUSTOM";
        }
    }

    if( bFileExists && nBandsIn > 0 && eDT == GDT_Byte )
    {
        // If there was an ogr_empty_table table, we can remove it
        RemoveOGREmptyTable();
    }

    SoftCommitTransaction();

    /* Requirement 2 */
    /* We have to do this after there's some content so the database file */
    /* is not zero length */
    SetApplicationAndUserVersionId();

    /* Default to synchronous=off for performance for new file */
    if( !bFileExists &&
        CPLGetConfigOption("OGR_SQLITE_SYNCHRONOUS", nullptr) == nullptr )
    {
        SQLCommand( hDB, "PRAGMA synchronous = OFF" );
    }

    m_bTableCreated = true;

    return TRUE;
}

/************************************************************************/
/*                     CreateOGREmptyTableIfNeeded()                    */
/************************************************************************/

void GDALGeoPackageDataset::CreateOGREmptyTableIfNeeded()
{
    // The specification makes it compulsory (Req 17) to have at least a
    // features or tiles table, so create a dummy one.
    if( m_bTableCreated &&
        !SQLGetInteger(hDB,
        "SELECT 1 FROM gpkg_contents WHERE data_type IN "
        "('features', 'tiles')", nullptr) &&
        CPLTestBool(CPLGetConfigOption("OGR_GPKG_CREATE_EMPTY_TABLE", "YES")) )
    {
        CPLDebug("GPKG", "Creating a dummy ogr_empty_table features table, "
                "since there is no features or tiles table.");
        const char* const apszLayerOptions[] = {
            "SPATIAL_INDEX=NO",
            "DESCRIPTION=Technical table needed to be conformant with "
                        "Requirement 17 of the GeoPackage specification",
            nullptr };
        CreateLayer("ogr_empty_table", nullptr, wkbUnknown,
                    const_cast<char**>(apszLayerOptions));
        // Effectively create the table
        FlushCache();
    }
}

/************************************************************************/
/*                        RemoveOGREmptyTable()                         */
/************************************************************************/

void GDALGeoPackageDataset::RemoveOGREmptyTable()
{
    // Run with sqlite3_exec since we don't want errors to be emitted
    sqlite3_exec( hDB,
        "DROP TABLE IF EXISTS ogr_empty_table", nullptr, nullptr, nullptr );
    sqlite3_exec( hDB,
        "DELETE FROM gpkg_contents WHERE table_name = 'ogr_empty_table'",
        nullptr, nullptr, nullptr );
#ifdef ENABLE_GPKG_OGR_CONTENTS
    if( m_bHasGPKGOGRContents )
    {
        sqlite3_exec( hDB,
            "DELETE FROM gpkg_ogr_contents WHERE "
            "table_name = 'ogr_empty_table'",
            nullptr, nullptr, nullptr );
    }
#endif
    sqlite3_exec( hDB,
        "DELETE FROM gpkg_geometry_columns WHERE "
        "table_name = 'ogr_empty_table'",
        nullptr, nullptr, nullptr );
}

/************************************************************************/
/*                        CreateTileGriddedTable()                      */
/************************************************************************/

bool GDALGeoPackageDataset::CreateTileGriddedTable(char** papszOptions)
{
    CPLString osSQL;
    if( !HasGriddedCoverageAncillaryTable() )
    {
        // It doesn't exist. So create gpkg_extensions table if necessary, and
        // gpkg_2d_gridded_coverage_ancillary & gpkg_2d_gridded_tile_ancillary,
        // and register them as extensions.
        if( CreateExtensionsTableIfNecessary() != OGRERR_NONE )
            return false;

        // Req 1 /table-defs/coverage-ancillary
        osSQL =
            "CREATE TABLE gpkg_2d_gridded_coverage_ancillary ("
            "id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,"
            "tile_matrix_set_name TEXT NOT NULL UNIQUE,"
            "datatype TEXT NOT NULL DEFAULT 'integer',"
            "scale REAL NOT NULL DEFAULT 1.0,"
            "offset REAL NOT NULL DEFAULT 0.0,"
            "precision REAL DEFAULT 1.0,"
            "data_null REAL,"
            "grid_cell_encoding TEXT DEFAULT 'grid-value-is-center',"
            "uom TEXT,"
            "field_name TEXT DEFAULT 'Height',"
            "quantity_definition TEXT DEFAULT 'Height',"
            "CONSTRAINT fk_g2dgtct_name FOREIGN KEY(tile_matrix_set_name) "
            "REFERENCES gpkg_tile_matrix_set ( table_name ) "
            "CHECK (datatype in ('integer','float')))"
            ";"
        // Requirement 2 /table-defs/tile-ancillary
            "CREATE TABLE gpkg_2d_gridded_tile_ancillary ("
            "id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,"
            "tpudt_name TEXT NOT NULL,"
            "tpudt_id INTEGER NOT NULL,"
            "scale REAL NOT NULL DEFAULT 1.0,"
            "offset REAL NOT NULL DEFAULT 0.0,"
            "min REAL DEFAULT NULL,"
            "max REAL DEFAULT NULL,"
            "mean REAL DEFAULT NULL,"
            "std_dev REAL DEFAULT NULL,"
            "CONSTRAINT fk_g2dgtat_name FOREIGN KEY (tpudt_name) "
            "REFERENCES gpkg_contents(table_name),"
            "UNIQUE (tpudt_name, tpudt_id))"
            ";"
        // Requirement 6 /gpkg-extensions
            "INSERT INTO gpkg_extensions "
            "(table_name, column_name, extension_name, definition, scope) "
            "VALUES ('gpkg_2d_gridded_coverage_ancillary', NULL, "
            "'gpkg_2d_gridded_coverage', "
            "'http://docs.opengeospatial.org/is/17-066r1/17-066r1.html', "
            "'read-write')"
            ";"
        // Requirement 6 /gpkg-extensions
            "INSERT INTO gpkg_extensions "
            "(table_name, column_name, extension_name, definition, scope) "
            "VALUES ('gpkg_2d_gridded_tile_ancillary', NULL, "
             "'gpkg_2d_gridded_coverage', "
            "'http://docs.opengeospatial.org/is/17-066r1/17-066r1.html', "
            "'read-write')"
            ";";
    }

    // Requirement 6 /gpkg-extensions
    char* pszSQL = sqlite3_mprintf(
        "INSERT INTO gpkg_extensions "
        "(table_name, column_name, extension_name, definition, scope) "
        "VALUES ('%q', 'tile_data', "
         "'gpkg_2d_gridded_coverage', "
        "'http://docs.opengeospatial.org/is/17-066r1/17-066r1.html', "
        "'read-write')", m_osRasterTable.c_str());
    osSQL += pszSQL;
    osSQL += ";";
    sqlite3_free(pszSQL);

    // Requirement 7 /gpkg-2d-gridded-coverage-ancillary
    // Requirement 8 /gpkg-2d-gridded-coverage-ancillary-set-name
    // Requirement 9 /gpkg-2d-gridded-coverage-ancillary-datatype
    m_dfPrecision = CPLAtof(CSLFetchNameValueDef(papszOptions,
                                                      "PRECISION", "1"));
    CPLString osGridCellEncoding(CSLFetchNameValueDef(
                papszOptions, "GRID_CELL_ENCODING", "grid-value-is-center"));
    m_bGridCellEncodingAsCO = 
        CSLFetchNameValue(papszOptions, "GRID_CELL_ENCODING") != nullptr;
    CPLString osUom(CSLFetchNameValueDef(papszOptions, "UOM", ""));
    CPLString osFieldName(
            CSLFetchNameValueDef(papszOptions, "FIELD_NAME", "Height"));
    CPLString osQuantityDefinition(CSLFetchNameValueDef(
                                papszOptions, "QUANTITY_DEFINITION", "Height"));

    pszSQL = sqlite3_mprintf(
        "INSERT INTO gpkg_2d_gridded_coverage_ancillary "
        "(tile_matrix_set_name, datatype, scale, offset, precision, "
        "grid_cell_encoding, uom, field_name, quantity_definition) "
        "VALUES ('%q', '%s', %.18g, %.18g, %.18g, %s, %s, %s, %s)",
        m_osRasterTable.c_str(),
        ( m_eTF == GPKG_TF_PNG_16BIT ) ? "integer" : "float",
        m_dfScale, m_dfOffset, m_dfPrecision,
        ("'" + SQLEscapeLiteral(osGridCellEncoding) + "'").c_str(),
        osUom.empty() ? "NULL" : ("'" + SQLEscapeLiteral(osUom) + "'").c_str(),
        ("'" + SQLEscapeLiteral(osFieldName) + "'").c_str(),
        ("'" + SQLEscapeLiteral(osQuantityDefinition) + "'").c_str());
    osSQL += pszSQL;
    sqlite3_free(pszSQL);

    // Requirement 3 /gpkg-spatial-ref-sys-row
    SQLResult oResultTable;
    OGRErr eErr = SQLQuery(hDB,
        "SELECT * FROM gpkg_spatial_ref_sys WHERE srs_id = 4979 LIMIT 2"
        , &oResultTable);
    bool bHasEPSG4979 = ( eErr == OGRERR_NONE && oResultTable.nRowCount == 1 );
    SQLResultFree(&oResultTable);
    if( !bHasEPSG4979 )
    {
        if( !m_bHasDefinition12_063 &&
            !ConvertGpkgSpatialRefSysToExtensionWkt2() )
        {
            return false;
        }

        // This is WKT 2...
        const char* pszWKT = "GEODCRS[\"WGS 84\","
  "DATUM[\"World Geodetic System 1984\","
  "  ELLIPSOID[\"WGS 84\",6378137,298.257223563,LENGTHUNIT[\"metre\",1.0]]],"
  "CS[ellipsoidal,3],"
  "  AXIS[\"latitude\",north,ORDER[1],ANGLEUNIT[\"degree\",0.01745329252]],"
  "  AXIS[\"longitude\",east,ORDER[2],ANGLEUNIT[\"degree\",0.01745329252]],"
  "  AXIS[\"ellipsoidal height\",up,ORDER[3],LENGTHUNIT[\"metre\",1.0]],"
  "ID[\"EPSG\",4979]]";

        pszSQL = sqlite3_mprintf(
            "INSERT INTO gpkg_spatial_ref_sys "
            "(srs_name,srs_id,organization,organization_coordsys_id,"
            "definition,definition_12_063) VALUES "
            "('WGS 84 3D', 4979, 'EPSG', 4979, 'undefined', '%q')",
            pszWKT);
        osSQL += ";";
        osSQL += pszSQL;
        sqlite3_free(pszSQL);
    }

    return SQLCommand(hDB, osSQL) == OGRERR_NONE;
}

/************************************************************************/
/*                    HasGriddedCoverageAncillaryTable()                */
/************************************************************************/

bool GDALGeoPackageDataset::HasGriddedCoverageAncillaryTable()
{
    SQLResult oResultTable;
    OGRErr eErr = SQLQuery(hDB,
        "SELECT * FROM sqlite_master WHERE type IN ('table', 'view') AND "
        "name = 'gpkg_2d_gridded_coverage_ancillary'"
        , &oResultTable);
    bool bHasTable = ( eErr == OGRERR_NONE && oResultTable.nRowCount == 1 );
    SQLResultFree(&oResultTable);
    return bHasTable;
}

/************************************************************************/
/*                      GetUnderlyingDataset()                          */
/************************************************************************/

static GDALDataset* GetUnderlyingDataset( GDALDataset* poSrcDS )
{
    if( EQUAL(poSrcDS->GetDescription(), "") &&
        poSrcDS->GetDriver() != nullptr &&
        poSrcDS->GetDriver() == GDALGetDriverByName("VRT") )
    {
        VRTDataset* poVRTDS = cpl::down_cast<VRTDataset*>(poSrcDS);
        auto poTmpDS = poVRTDS->GetSingleSimpleSource();
        if( poTmpDS )
            return poTmpDS;
    }

    return poSrcDS;
}
/************************************************************************/
/*                            CreateCopy()                              */
/************************************************************************/

typedef struct
{
    const char*         pszName;
    GDALResampleAlg     eResampleAlg;
} WarpResamplingAlg;

static const WarpResamplingAlg asResamplingAlg[] =
{
    { "NEAREST", GRA_NearestNeighbour },
    { "BILINEAR", GRA_Bilinear },
    { "CUBIC", GRA_Cubic },
    { "CUBICSPLINE", GRA_CubicSpline },
    { "LANCZOS", GRA_Lanczos },
    { "MODE", GRA_Mode },
    { "AVERAGE", GRA_Average },
};

GDALDataset* GDALGeoPackageDataset::CreateCopy( const char *pszFilename,
                                                   GDALDataset *poSrcDS,
                                                   int bStrict,
                                                   char ** papszOptions,
                                                   GDALProgressFunc pfnProgress,
                                                   void * pProgressData )
{
    const char* pszTilingScheme =
            CSLFetchNameValueDef(papszOptions, "TILING_SCHEME", "CUSTOM");

    CPLStringList apszUpdatedOptions(CSLDuplicate(papszOptions));
    if( CPLTestBool(CSLFetchNameValueDef(papszOptions, "APPEND_SUBDATASET", "NO")) &&
        CSLFetchNameValue(papszOptions, "RASTER_TABLE") == nullptr )
    {
        CPLString osBasename(CPLGetBasename(GetUnderlyingDataset(poSrcDS)->GetDescription()));
        apszUpdatedOptions.SetNameValue("RASTER_TABLE", osBasename);
    }

    const int nBands = poSrcDS->GetRasterCount();
    if( nBands != 1 && nBands != 2 && nBands != 3 && nBands != 4 )
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Only 1 (Grey/ColorTable), 2 (Grey+Alpha), 3 (RGB) or "
                 "4 (RGBA) band dataset supported");
        return nullptr;
    }

    const char* pszUnitType = poSrcDS->GetRasterBand(1)->GetUnitType();
    if( CSLFetchNameValue(papszOptions, "UOM") == nullptr &&
        pszUnitType && !EQUAL(pszUnitType, "") )
    {
        apszUpdatedOptions.SetNameValue("UOM", pszUnitType);
    }

    if( EQUAL(pszTilingScheme, "CUSTOM") )
    {
        GDALDataset* poDS = nullptr;
        GDALDriver* poThisDriver = reinterpret_cast<GDALDriver*>(
                                                GDALGetDriverByName("GPKG"));
        if( poThisDriver != nullptr )
        {
            poDS = poThisDriver->DefaultCreateCopy(
                pszFilename, poSrcDS, bStrict,
                apszUpdatedOptions, pfnProgress, pProgressData );
        }
        return poDS;
    }

    bool bFound = false;
    int nEPSGCode = 0;
    size_t iScheme = 0;  // Used after for.
    for( ;
         iScheme < sizeof(asTilingShemes)/sizeof(asTilingShemes[0]);
         iScheme++ )
    {
        if( EQUAL(pszTilingScheme, asTilingShemes[iScheme].pszName) )
        {
            nEPSGCode = asTilingShemes[iScheme].nEPSGCode;
            bFound = true;
            break;
        }
    }
    if( !bFound )
    {
        return nullptr;
    }

    OGRSpatialReference oSRS;
    if( oSRS.importFromEPSG(nEPSGCode) != OGRERR_NONE )
    {
        return nullptr;
    }
    char* pszWKT = nullptr;
    oSRS.exportToWkt(&pszWKT);
    char** papszTO = CSLSetNameValue( nullptr, "DST_SRS", pszWKT );
    void* hTransformArg =
            GDALCreateGenImgProjTransformer2( poSrcDS, nullptr, papszTO );
    if( hTransformArg == nullptr )
    {
        CPLFree(pszWKT);
        CSLDestroy(papszTO);
        return nullptr;
    }

    GDALTransformerInfo* psInfo = (GDALTransformerInfo*)hTransformArg;
    double adfGeoTransform[6];
    double adfExtent[4];
    int    nXSize, nYSize;

    if ( GDALSuggestedWarpOutput2( poSrcDS,
                                  psInfo->pfnTransform, hTransformArg,
                                  adfGeoTransform,
                                  &nXSize, &nYSize,
                                  adfExtent, 0 ) != CE_None )
    {
        CPLFree(pszWKT);
        CSLDestroy(papszTO);
        GDALDestroyGenImgProjTransformer( hTransformArg );
        return nullptr;
    }

    GDALDestroyGenImgProjTransformer( hTransformArg );
    hTransformArg = nullptr;

    // Hack to compensate for GDALSuggestedWarpOutput2() failure when
    // reprojection latitude = +/- 90 to EPSG:3857.
    double adfSrcGeoTransform[6];
    if( nEPSGCode == 3857 && poSrcDS->GetGeoTransform(adfSrcGeoTransform) == CE_None )
    {
        const char* pszSrcWKT = poSrcDS->GetProjectionRef();
        if( pszSrcWKT != nullptr && pszSrcWKT[0] != '\0' )
        {
            OGRSpatialReference oSrcSRS;
            if( oSrcSRS.SetFromUserInput( pszSrcWKT ) == OGRERR_NONE &&
                oSrcSRS.IsGeographic() )
            {
                const double minLat =
                    std::min(adfSrcGeoTransform[3],
                             adfSrcGeoTransform[3] +
                             poSrcDS->GetRasterYSize() *
                             adfSrcGeoTransform[5]);
                const double maxLat =
                    std::max(adfSrcGeoTransform[3],
                             adfSrcGeoTransform[3] +
                             poSrcDS->GetRasterYSize() *
                             adfSrcGeoTransform[5]);
                double maxNorthing = adfGeoTransform[3];
                double minNorthing =
                    adfGeoTransform[3] + adfGeoTransform[5] * nYSize;
                bool bChanged = false;
                const double SPHERICAL_RADIUS = 6378137.0;
                const double MAX_GM =
                    SPHERICAL_RADIUS * M_PI;  // 20037508.342789244
                if( maxLat > 89.9999999 )
                {
                    bChanged = true;
                    maxNorthing = MAX_GM;
                }
                if( minLat <= -89.9999999 )
                {
                    bChanged = true;
                    minNorthing = -MAX_GM;
                }
                if( bChanged )
                {
                    adfGeoTransform[3] = maxNorthing;
                    nYSize = int((maxNorthing - minNorthing) / (-adfGeoTransform[5]) + 0.5);
                    adfExtent[1] = maxNorthing + nYSize * adfGeoTransform[5];
                    adfExtent[3] = maxNorthing;
                }
            }
        }
    }

    double dfComputedRes = adfGeoTransform[1];
    double dfPrevRes = 0.0;
    double dfRes = 0.0;
    int nZoomLevel = 0;  // Used after for.
    for( ; nZoomLevel < 25; nZoomLevel++ )
    {
        dfRes = asTilingShemes[iScheme].dfPixelXSizeZoomLevel0 / (1 << nZoomLevel);
        if( dfComputedRes > dfRes )
            break;
        dfPrevRes = dfRes;
    }
    if( nZoomLevel == 25 )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Could not find an appropriate zoom level");
        CPLFree(pszWKT);
        CSLDestroy(papszTO);
        return nullptr;
    }

    const char* pszZoomLevelStrategy = CSLFetchNameValueDef(papszOptions,
                                                            "ZOOM_LEVEL_STRATEGY",
                                                            "AUTO");
    if( fabs( dfComputedRes - dfRes ) / dfRes > 1e-8 )
    {
        if( EQUAL(pszZoomLevelStrategy, "LOWER") )
        {
            if( nZoomLevel > 0 )
                nZoomLevel --;
        }
        else if( EQUAL(pszZoomLevelStrategy, "UPPER") )
        {
            /* do nothing */
        }
        else if( nZoomLevel > 0 )
        {
            if( dfPrevRes / dfComputedRes < dfComputedRes / dfRes )
                nZoomLevel --;
        }
    }

    dfRes = asTilingShemes[iScheme].dfPixelXSizeZoomLevel0 / (1 << nZoomLevel);

    double dfMinX = adfExtent[0];
    double dfMinY = adfExtent[1];
    double dfMaxX = adfExtent[2];
    double dfMaxY = adfExtent[3];

    nXSize = (int) ( 0.5 + ( dfMaxX - dfMinX ) / dfRes );
    nYSize = (int) ( 0.5 + ( dfMaxY - dfMinY ) / dfRes );
    adfGeoTransform[1] = dfRes;
    adfGeoTransform[5] = -dfRes;

    const GDALDataType eDT = poSrcDS->GetRasterBand(1)->GetRasterDataType();
    int nTargetBands = nBands;
    /* For grey level or RGB, if there's reprojection involved, add an alpha */
    /* channel */
    if( eDT == GDT_Byte &&
        ((nBands == 1 && poSrcDS->GetRasterBand(1)->GetColorTable() == nullptr) ||
        nBands == 3) )
    {
        OGRSpatialReference oSrcSRS;
        oSrcSRS.SetFromUserInput(poSrcDS->GetProjectionRef());
        oSrcSRS.AutoIdentifyEPSG();
        if( oSrcSRS.GetAuthorityCode(nullptr) == nullptr ||
            atoi(oSrcSRS.GetAuthorityCode(nullptr)) != nEPSGCode )
        {
            nTargetBands ++;
        }
    }

    GDALResampleAlg eResampleAlg = GRA_Bilinear;
    const char* pszResampling = CSLFetchNameValue(papszOptions, "RESAMPLING");
    if( pszResampling )
    {
        for(size_t iAlg = 0; iAlg < sizeof(asResamplingAlg)/sizeof(asResamplingAlg[0]); iAlg ++)
        {
            if( EQUAL(pszResampling, asResamplingAlg[iAlg].pszName) )
            {
                eResampleAlg = asResamplingAlg[iAlg].eResampleAlg;
                break;
            }
        }
    }

    if( nBands == 1 && poSrcDS->GetRasterBand(1)->GetColorTable() != nullptr &&
        eResampleAlg != GRA_NearestNeighbour && eResampleAlg != GRA_Mode )
    {
        CPLError(CE_Warning, CPLE_AppDefined,
                 "Input dataset has a color table, which will likely lead to "
                 "bad results when using a resampling method other than "
                 "nearest neighbour or mode. Converting the dataset to 24/32 bit "
                 "(e.g. with gdal_translate -expand rgb/rgba) is advised.");
    }

    GDALGeoPackageDataset* poDS = new GDALGeoPackageDataset();
    if( !(poDS->Create( pszFilename, nXSize, nYSize, nTargetBands, eDT,
                        apszUpdatedOptions )) )
    {
        delete poDS;
        CPLFree(pszWKT);
        CSLDestroy(papszTO);
        return nullptr;
    }

    poDS->SetGeoTransform(adfGeoTransform);
    poDS->SetProjection(pszWKT);
    CPLFree(pszWKT);
    pszWKT = nullptr;
    if( nTargetBands == 1 && nBands == 1 && poSrcDS->GetRasterBand(1)->GetColorTable() != nullptr )
    {
        poDS->GetRasterBand(1)->SetColorTable( poSrcDS->GetRasterBand(1)->GetColorTable() );
    }

    int bHasNoData = FALSE;
    double dfNoDataValue =
            poSrcDS->GetRasterBand(1)->GetNoDataValue(&bHasNoData);
    if( eDT != GDT_Byte && bHasNoData )
    {
        poDS->GetRasterBand(1)->SetNoDataValue(dfNoDataValue);
    }

    hTransformArg =
        GDALCreateGenImgProjTransformer2( poSrcDS, poDS, papszTO );
    CSLDestroy(papszTO);
    if( hTransformArg == nullptr )
    {
        delete poDS;
        return nullptr;
    }

    poDS->SetMetadata( poSrcDS->GetMetadata() );

/* -------------------------------------------------------------------- */
/*      Warp the transformer with a linear approximator                 */
/* -------------------------------------------------------------------- */
    hTransformArg =
        GDALCreateApproxTransformer( GDALGenImgProjTransform,
                                     hTransformArg, 0.125 );
    GDALApproxTransformerOwnsSubtransformer(hTransformArg, TRUE);

/* -------------------------------------------------------------------- */
/*      Setup warp options.                                             */
/* -------------------------------------------------------------------- */
    GDALWarpOptions *psWO = GDALCreateWarpOptions();

    psWO->papszWarpOptions = CSLSetNameValue(nullptr, "OPTIMIZE_SIZE", "YES");
    if( bHasNoData )
    {
        if( dfNoDataValue == 0.0 )
        {
            // Do not initialize in the case where nodata != 0, since we
            // want the GeoPackage driver to return empty tiles at the nodata
            // value instead of 0 as GDAL core would
            psWO->papszWarpOptions = CSLSetNameValue(psWO->papszWarpOptions,
                                                 "INIT_DEST", "0");
        }

        psWO->padfSrcNoDataReal =
            static_cast<double*>(CPLMalloc(sizeof(double)));
        psWO->padfSrcNoDataReal[0] = dfNoDataValue;

        psWO->padfDstNoDataReal =
            static_cast<double*>(CPLMalloc(sizeof(double)));
        psWO->padfDstNoDataReal[0] = dfNoDataValue;
    }
    psWO->eWorkingDataType = eDT;
    psWO->eResampleAlg = eResampleAlg;

    psWO->hSrcDS = poSrcDS;
    psWO->hDstDS = poDS;

    psWO->pfnTransformer = GDALApproxTransform;
    psWO->pTransformerArg = hTransformArg;

    psWO->pfnProgress = pfnProgress;
    psWO->pProgressArg = pProgressData;

/* -------------------------------------------------------------------- */
/*      Setup band mapping.                                             */
/* -------------------------------------------------------------------- */

    if( nBands == 2 || nBands == 4 )
        psWO->nBandCount = nBands - 1;
    else
        psWO->nBandCount = nBands;

    psWO->panSrcBands = (int *) CPLMalloc(psWO->nBandCount*sizeof(int));
    psWO->panDstBands = (int *) CPLMalloc(psWO->nBandCount*sizeof(int));

    for( int i = 0; i < psWO->nBandCount; i++ )
    {
        psWO->panSrcBands[i] = i+1;
        psWO->panDstBands[i] = i+1;
    }

    if( nBands == 2 || nBands == 4 )
    {
        psWO->nSrcAlphaBand = nBands;
    }
    if( nTargetBands == 2 || nTargetBands == 4 )
    {
        psWO->nDstAlphaBand = nTargetBands;
    }

/* -------------------------------------------------------------------- */
/*      Initialize and execute the warp.                                */
/* -------------------------------------------------------------------- */
    GDALWarpOperation oWO;

    CPLErr eErr = oWO.Initialize( psWO );
    if( eErr == CE_None )
    {
        /*if( bMulti )
            eErr = oWO.ChunkAndWarpMulti( 0, 0, nXSize, nYSize );
        else*/
        eErr = oWO.ChunkAndWarpImage( 0, 0, nXSize, nYSize );
    }
    if (eErr != CE_None)
    {
        delete poDS;
        poDS = nullptr;
    }

    GDALDestroyTransformer( hTransformArg );
    GDALDestroyWarpOptions( psWO );

    return poDS;
}

/************************************************************************/
/*                        ParseCompressionOptions()                     */
/************************************************************************/

void GDALGeoPackageDataset::ParseCompressionOptions(char** papszOptions)
{
    const char* pszZLevel = CSLFetchNameValue(papszOptions, "ZLEVEL");
    if( pszZLevel )
        m_nZLevel = atoi(pszZLevel);

    const char* pszQuality = CSLFetchNameValue(papszOptions, "QUALITY");
    if( pszQuality )
        m_nQuality = atoi(pszQuality);

    const char* pszDither = CSLFetchNameValue(papszOptions, "DITHER");
    if( pszDither )
        m_bDither = CPLTestBool(pszDither);
}

/************************************************************************/
/*                          RegisterWebPExtension()                     */
/************************************************************************/

bool GDALGeoPackageDataset::RegisterWebPExtension()
{
    if( CreateExtensionsTableIfNecessary() != OGRERR_NONE )
        return false;

    char* pszSQL = sqlite3_mprintf(
        "INSERT INTO gpkg_extensions "
        "(table_name, column_name, extension_name, definition, scope) "
        "VALUES "
        "('%q', 'tile_data', 'gpkg_webp', 'http://www.geopackage.org/spec120/#extension_tiles_webp', 'read-write')",
        m_osRasterTable.c_str());
    const OGRErr eErr = SQLCommand(hDB, pszSQL);
    sqlite3_free(pszSQL);

    return OGRERR_NONE == eErr;
}

/************************************************************************/
/*                       RegisterZoomOtherExtension()                   */
/************************************************************************/

bool GDALGeoPackageDataset::RegisterZoomOtherExtension()
{
    if( CreateExtensionsTableIfNecessary() != OGRERR_NONE )
        return false;

    char* pszSQL = sqlite3_mprintf(
        "INSERT INTO gpkg_extensions "
        "(table_name, column_name, extension_name, definition, scope) "
        "VALUES "
        "('%q', 'tile_data', 'gpkg_zoom_other', 'http://www.geopackage.org/spec120/#extension_zoom_other_intervals', 'read-write')",
        m_osRasterTable.c_str());
    const OGRErr eErr = SQLCommand(hDB, pszSQL);
    sqlite3_free(pszSQL);
    return OGRERR_NONE == eErr;
}

/************************************************************************/
/*                              GetLayer()                              */
/************************************************************************/

OGRLayer* GDALGeoPackageDataset::GetLayer( int iLayer )

{
    if( iLayer < 0 || iLayer >= m_nLayers )
        return nullptr;
    else
        return m_papoLayers[iLayer];
}

/************************************************************************/
/*                          ICreateLayer()                              */
/* Options:                                                             */
/*   FID = primary key name                                             */
/*   OVERWRITE = YES|NO, overwrite existing layer?                      */
/*   SPATIAL_INDEX = YES|NO, TBD                                        */
/************************************************************************/

OGRLayer* GDALGeoPackageDataset::ICreateLayer( const char * pszLayerName,
                                      OGRSpatialReference * poSpatialRef,
                                      OGRwkbGeometryType eGType,
                                      char **papszOptions )
{
/* -------------------------------------------------------------------- */
/*      Verify we are in update mode.                                   */
/* -------------------------------------------------------------------- */
    if( !bUpdate )
    {
        CPLError( CE_Failure, CPLE_NoWriteAccess,
                  "Data source %s opened read-only.\n"
                  "New layer %s cannot be created.\n",
                  m_pszFilename, pszLayerName );

        return nullptr;
    }

    if( !m_bHasGPKGGeometryColumns )
    {
        if( SQLCommand( hDB, pszCREATE_GPKG_GEOMETRY_COLUMNS ) != OGRERR_NONE )
        {
            return nullptr;
        }
        m_bHasGPKGGeometryColumns = true;
    }

    // Check identifier unicity
    const char* pszIdentifier = CSLFetchNameValue(papszOptions, "IDENTIFIER");
    if( pszIdentifier != nullptr && pszIdentifier[0] == '\0' )
        pszIdentifier = nullptr;
    if( pszIdentifier != nullptr )
    {
        for(int i = 0; i < m_nLayers; ++i )
        {
            const char* pszOtherIdentifier =
                m_papoLayers[i]->GetMetadataItem("IDENTIFIER");
            if( pszOtherIdentifier == nullptr )
                pszOtherIdentifier = m_papoLayers[i]->GetName();
            if( pszOtherIdentifier != nullptr &&
                EQUAL(pszOtherIdentifier, pszIdentifier) &&
                !EQUAL(m_papoLayers[i]->GetName(), pszLayerName) )
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                     "Identifier %s is already used by table %s",
                     pszIdentifier, m_papoLayers[i]->GetName());
                return nullptr;
            }
        }

        // In case there would be table in gpkg_contents not listed as a
        // vector layer
        char* pszSQL = sqlite3_mprintf(
            "SELECT table_name FROM gpkg_contents WHERE identifier = '%q' "
            "LIMIT 2",
            pszIdentifier);
        SQLResult oResult;
        OGRErr eErr = SQLQuery (hDB, pszSQL, &oResult);
        sqlite3_free(pszSQL);
        if( eErr == OGRERR_NONE && oResult.nRowCount > 0 &&
            SQLResultGetValue(&oResult, 0, 0) != nullptr &&
            !EQUAL(SQLResultGetValue(&oResult, 0, 0), pszLayerName) )
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Identifier %s is already used by table %s",
                     pszIdentifier, SQLResultGetValue(&oResult, 0, 0));
            SQLResultFree(&oResult);
            return nullptr;
        }
        SQLResultFree(&oResult);
    }

    /* Read GEOMETRY_NAME option */
    const char* pszGeomColumnName = CSLFetchNameValue(papszOptions, "GEOMETRY_NAME");
    if (pszGeomColumnName == nullptr) /* deprecated name */
        pszGeomColumnName = CSLFetchNameValue(papszOptions, "GEOMETRY_COLUMN");
    if (pszGeomColumnName == nullptr)
        pszGeomColumnName = "geom";
    const bool bGeomNullable =
        CPLFetchBool(papszOptions, "GEOMETRY_NULLABLE", true);

    /* Read FID option */
    const char* pszFIDColumnName = CSLFetchNameValue(papszOptions, "FID");
    if (pszFIDColumnName == nullptr)
        pszFIDColumnName = "fid";

    if( CPLTestBool(CPLGetConfigOption("GPKG_NAME_CHECK", "YES")) )
    {
    if ( strspn(pszFIDColumnName, "`~!@#$%^&*()+-={}|[]\\:\";'<>?,./") > 0 )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "The primary key (%s) name may not contain special characters or spaces",
                 pszFIDColumnName);
        return nullptr;
    }

    /* Avoiding gpkg prefixes is not an official requirement, but seems wise */
    if (STARTS_WITH(pszLayerName, "gpkg"))
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "The layer name may not begin with 'gpkg' as it is a reserved geopackage prefix");
        return nullptr;
    }

    /* Preemptively try and avoid sqlite3 syntax errors due to  */
    /* illegal characters. */
    if ( strspn(pszLayerName, "`~!@#$%^&*()+-={}|[]\\:\";'<>?,./") > 0 )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "The layer name may not contain special characters or spaces");
        return nullptr;
    }
    }

    /* Check for any existing layers that already use this name */
    for( int iLayer = 0; iLayer < m_nLayers; iLayer++ )
    {
        if( EQUAL(pszLayerName, m_papoLayers[iLayer]->GetName()) )
        {
            const char *pszOverwrite = CSLFetchNameValue(papszOptions,"OVERWRITE");
            if( pszOverwrite != nullptr && CPLTestBool(pszOverwrite) )
            {
                DeleteLayer( iLayer );
            }
            else
            {
                CPLError( CE_Failure, CPLE_AppDefined,
                          "Layer %s already exists, CreateLayer failed.\n"
                          "Use the layer creation option OVERWRITE=YES to "
                          "replace it.",
                          pszLayerName );
                return nullptr;
            }
        }
    }

    /* Create a blank layer. */
    OGRGeoPackageTableLayer *poLayer = new OGRGeoPackageTableLayer(this, pszLayerName);

    OGRSpatialReference* poSRS = nullptr;
    if( poSpatialRef )
    {
        poSRS = poSpatialRef->Clone();
        poSRS->SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
    }
    poLayer->SetCreationParameters( eGType, pszGeomColumnName,
                                    bGeomNullable,
                                    poSRS,
                                    pszFIDColumnName,
                                    pszIdentifier,
                                    CSLFetchNameValue(papszOptions, "DESCRIPTION") );
    if( poSRS )
    {
        poSRS->Release();
    }

    /* Should we create a spatial index ? */
    const char *pszSI = CSLFetchNameValue( papszOptions, "SPATIAL_INDEX" );
    int bCreateSpatialIndex = ( pszSI == nullptr || CPLTestBool(pszSI) );
    if( eGType != wkbNone && bCreateSpatialIndex )
    {
        poLayer->SetDeferredSpatialIndexCreation(true);
    }

    poLayer->SetPrecisionFlag( CPLFetchBool(papszOptions, "PRECISION", true) );
    poLayer->SetTruncateFieldsFlag(
        CPLFetchBool(papszOptions, "TRUNCATE_FIELDS", false));
    if( eGType == wkbNone )
    {
        const char* pszASpatialVariant = CSLFetchNameValueDef(papszOptions,
                                                            "ASPATIAL_VARIANT",
                                                            "GPKG_ATTRIBUTES");
        GPKGASpatialVariant eASPatialVariant = GPKG_ATTRIBUTES;
        if( EQUAL(pszASpatialVariant, "GPKG_ATTRIBUTES") )
            eASPatialVariant = GPKG_ATTRIBUTES;
        else if( EQUAL(pszASpatialVariant, "OGR_ASPATIAL") )
            eASPatialVariant = OGR_ASPATIAL;
        else if( EQUAL(pszASpatialVariant, "NOT_REGISTERED") )
            eASPatialVariant = NOT_REGISTERED;
        else
        {
            CPLError(CE_Warning, CPLE_NotSupported,
                     "Unsupported value for ASPATIAL_VARIANT: %s",
                     pszASpatialVariant);
        }
        poLayer->SetASpatialVariant( eASPatialVariant );
    }

    // If there was an ogr_empty_table table, we can remove it
    if( strcmp(pszLayerName, "ogr_empty_table") != 0 &&
        eGType != wkbNone )
    {
        RemoveOGREmptyTable();
    }

    m_bTableCreated = true;

    m_papoLayers = (OGRGeoPackageTableLayer**)CPLRealloc(m_papoLayers,  sizeof(OGRGeoPackageTableLayer*) * (m_nLayers+1));
    m_papoLayers[m_nLayers++] = poLayer;
    return poLayer;
}

/************************************************************************/
/*                          FindLayerIndex()                            */
/************************************************************************/

int GDALGeoPackageDataset::FindLayerIndex( const char *pszLayerName )

{
    for( int iLayer = 0; iLayer < m_nLayers; iLayer++ )
    {
        if( EQUAL(pszLayerName,m_papoLayers[iLayer]->GetName()) )
            return iLayer;
    }
    return -1;
}

/************************************************************************/
/*                       DeleteLayerCommon()                            */
/************************************************************************/

OGRErr GDALGeoPackageDataset::DeleteLayerCommon(const char* pszLayerName)
{
    char* pszSQL = sqlite3_mprintf(
            "DELETE FROM gpkg_contents WHERE lower(table_name) = lower('%q')",
            pszLayerName);
    OGRErr eErr = SQLCommand(hDB, pszSQL);
    sqlite3_free(pszSQL);

    if( eErr == OGRERR_NONE && HasExtensionsTable() )
    {
        pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_extensions WHERE lower(table_name) = lower('%q')",
                pszLayerName);
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }

    if( eErr == OGRERR_NONE && HasMetadataTables() )
    {
        // Delete from gpkg_metadata metadata records that are only referenced
        // by the table we are about to drop
        pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_metadata WHERE id IN ("
                "SELECT DISTINCT md_file_id FROM "
                "gpkg_metadata_reference WHERE "
                "lower(table_name) = lower('%q') AND md_parent_id is NULL) "
                "AND id NOT IN ("
                "SELECT DISTINCT md_file_id FROM gpkg_metadata_reference WHERE "
                "md_file_id IN (SELECT DISTINCT md_file_id FROM "
                "gpkg_metadata_reference WHERE "
                "lower(table_name) = lower('%q') AND md_parent_id is NULL) "
                "AND lower(table_name) <> lower('%q'))",
                pszLayerName,
                pszLayerName,
                pszLayerName);
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);

        if( eErr == OGRERR_NONE )
        {
            pszSQL = sqlite3_mprintf(
                    "DELETE FROM gpkg_metadata_reference WHERE "
                    "lower(table_name) = lower('%q')",
                    pszLayerName);
            eErr = SQLCommand(hDB, pszSQL);
            sqlite3_free(pszSQL);
        }
    }

    if( eErr == OGRERR_NONE )
    {
        pszSQL = sqlite3_mprintf("DROP TABLE \"%w\"", pszLayerName);
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }

    // Check foreign key integrity
    if ( eErr == OGRERR_NONE )
    {
        eErr = PragmaCheck("foreign_key_check", "", 0);
    }

    return eErr;
}

/************************************************************************/
/*                            DeleteLayer()                             */
/************************************************************************/

OGRErr GDALGeoPackageDataset::DeleteLayer( int iLayer )
{
    if( !bUpdate || iLayer < 0 || iLayer >= m_nLayers )
        return OGRERR_FAILURE;

    m_papoLayers[iLayer]->ResetReading();
    m_papoLayers[iLayer]->SyncToDisk();

    CPLString osLayerName = m_papoLayers[iLayer]->GetName();

    CPLDebug( "GPKG", "DeleteLayer(%s)", osLayerName.c_str() );

    OGRErr eErr = SoftStartTransaction();

    if( eErr == OGRERR_NONE )
    {
        if( m_papoLayers[iLayer]->HasSpatialIndex() )
            m_papoLayers[iLayer]->DropSpatialIndex();

        char* pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_geometry_columns WHERE "
                "lower(table_name) = lower('%q')",
                osLayerName.c_str());
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }

    if( eErr == OGRERR_NONE && HasDataColumnsTable() )
    {
        char* pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_data_columns WHERE lower(table_name) = lower('%q')",
                osLayerName.c_str());
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }

#ifdef ENABLE_GPKG_OGR_CONTENTS
    if( eErr == OGRERR_NONE && m_bHasGPKGOGRContents )
    {
        char* pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_ogr_contents WHERE lower(table_name) = lower('%q')",
                osLayerName.c_str());
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }
#endif

    if( eErr == OGRERR_NONE )
    {
        eErr = DeleteLayerCommon(osLayerName.c_str());
    }

    if( eErr == OGRERR_NONE )
    {
        eErr = SoftCommitTransaction();
        if( eErr == OGRERR_NONE )
        {
            /* Delete the layer object and remove the gap in the layers list */
            delete m_papoLayers[iLayer];
            memmove( m_papoLayers + iLayer, m_papoLayers + iLayer + 1,
                    sizeof(void *) * (m_nLayers - iLayer - 1) );
            m_nLayers--;
        }
    }
    else
    {
        SoftRollbackTransaction();
    }

    return eErr;
}

/************************************************************************/
/*                       DeleteRasterLayer()                            */
/************************************************************************/

OGRErr GDALGeoPackageDataset::DeleteRasterLayer( const char* pszLayerName )
{

    OGRErr eErr = SoftStartTransaction();

    if( eErr == OGRERR_NONE)
    {
        char* pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_tile_matrix WHERE lower(table_name) = lower('%q')",
                pszLayerName);
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }

    if( eErr == OGRERR_NONE )
    {
        char* pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_tile_matrix_set WHERE lower(table_name) = lower('%q')",
                pszLayerName);
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);
    }

    if( eErr == OGRERR_NONE && HasGriddedCoverageAncillaryTable() )
    {
        char* pszSQL = sqlite3_mprintf(
                "DELETE FROM gpkg_2d_gridded_coverage_ancillary WHERE lower(tile_matrix_set_name) = lower('%q')",
                pszLayerName);
        eErr = SQLCommand(hDB, pszSQL);
        sqlite3_free(pszSQL);

        if( eErr == OGRERR_NONE )
        {
            pszSQL = sqlite3_mprintf(
                    "DELETE FROM gpkg_2d_gridded_tile_ancillary WHERE lower(tpudt_name) = lower('%q')",
                    pszLayerName);
            eErr = SQLCommand(hDB, pszSQL);
            sqlite3_free(pszSQL);
        }
    }

    if( eErr == OGRERR_NONE )
    {
        eErr = DeleteLayerCommon(pszLayerName);
    }

    if( eErr == OGRERR_NONE )
    {
        eErr = SoftCommitTransaction();
    }
    else
    {
        SoftRollbackTransaction();
    }
    
    return eErr;
}

/************************************************************************/
/*                    DeleteVectorOrRasterLayer()                       */
/************************************************************************/

bool GDALGeoPackageDataset::DeleteVectorOrRasterLayer(
                                                const char* pszLayerName )
{

    int idx = FindLayerIndex( pszLayerName );
    if( idx >= 0 )
    {
        DeleteLayer( idx );
        return true;
    }

    char* pszSQL = sqlite3_mprintf(
            "SELECT 1 FROM gpkg_contents WHERE "
            "lower(table_name) = lower('%q') "
            "AND data_type IN ('tiles', '2d-gridded-coverage')",
            pszLayerName);
    bool bIsRasterTable = SQLGetInteger(hDB, pszSQL, nullptr) == 1;
    sqlite3_free(pszSQL);
    if( bIsRasterTable )
    {
        DeleteRasterLayer(pszLayerName);
        return true;
    }
    return false;
}


/************************************************************************/
/*                       TestCapability()                               */
/************************************************************************/

int GDALGeoPackageDataset::TestCapability( const char * pszCap )
{
    if ( EQUAL(pszCap,ODsCCreateLayer) ||
         EQUAL(pszCap,ODsCDeleteLayer) ||
         EQUAL(pszCap,"RenameLayer") )
    {
         return bUpdate;
    }
    else if( EQUAL(pszCap,ODsCCurveGeometries) )
        return TRUE;
    else if( EQUAL(pszCap,ODsCMeasuredGeometries) )
        return TRUE;
    else if( EQUAL(pszCap,ODsCRandomLayerWrite) )
        return bUpdate;

    return OGRSQLiteBaseDataSource::TestCapability(pszCap);
}

/************************************************************************/
/*                       ResetReadingAllLayers()                        */
/************************************************************************/

void GDALGeoPackageDataset::ResetReadingAllLayers()
{
    for( int i = 0; i < m_nLayers; i++ )
    {
        m_papoLayers[i]->ResetReading();
    }
}

/************************************************************************/
/*                             ExecuteSQL()                             */
/************************************************************************/

static const char* const apszFuncsWithSideEffects[] =
{
    "CreateSpatialIndex",
    "DisableSpatialIndex",
    "HasSpatialIndex",
};

OGRLayer * GDALGeoPackageDataset::ExecuteSQL( const char *pszSQLCommand,
                                          OGRGeometry *poSpatialFilter,
                                          const char *pszDialect )

{
    m_bHasReadMetadataFromStorage = false;

    FlushMetadata();

    CPLString osSQLCommand(pszSQLCommand);
    if( !osSQLCommand.empty() && osSQLCommand.back() == ';' )
        osSQLCommand.resize(osSQLCommand.size() - 1);

    if( pszDialect == nullptr || !EQUAL(pszDialect, "DEBUG") )
    {
        // Some SQL commands will influence the feature count behind our
        // back, so disable it in that case.
#ifdef ENABLE_GPKG_OGR_CONTENTS
        const bool bInsertOrDelete =
            osSQLCommand.ifind("insert into ") != std::string::npos ||
            osSQLCommand.ifind("delete from ") != std::string::npos;
        const bool bRollback = osSQLCommand.ifind("rollback ") != std::string::npos;
#endif

        for( int i = 0; i < m_nLayers; i++ )
        {
#ifdef ENABLE_GPKG_OGR_CONTENTS
            if( bRollback ||
                (bInsertOrDelete &&
                 osSQLCommand.ifind(m_papoLayers[i]->GetName()) != std::string::npos) )
            {
                m_papoLayers[i]->DisableFeatureCount();
            }
#endif
            m_papoLayers[i]->SyncToDisk();
        }
    }

/* -------------------------------------------------------------------- */
/*      Special case DELLAYER: command.                                 */
/* -------------------------------------------------------------------- */
    if( STARTS_WITH_CI(osSQLCommand, "DELLAYER:") )
    {
        const char *pszLayerName = osSQLCommand.c_str() + strlen("DELLAYER:");

        while( *pszLayerName == ' ' )
            pszLayerName++;

        if( !DeleteVectorOrRasterLayer(pszLayerName) )
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Unknown layer: %s",
                     pszLayerName);
        }
        return nullptr;
    }

/* -------------------------------------------------------------------- */
/*      Special case RECOMPUTE EXTENT ON command.                       */
/* -------------------------------------------------------------------- */
    if( STARTS_WITH_CI(osSQLCommand, "RECOMPUTE EXTENT ON ") )
    {
        const char *pszLayerName = osSQLCommand.c_str() + strlen("RECOMPUTE EXTENT ON ");

        while( *pszLayerName == ' ' )
            pszLayerName++;

        int idx = FindLayerIndex( pszLayerName );
        if( idx >= 0 )
        {
            m_papoLayers[idx]->RecomputeExtent();
        }
        else
            CPLError(CE_Failure, CPLE_AppDefined, "Unknown layer: %s",
                     pszLayerName);
        return nullptr;
    }

/* -------------------------------------------------------------------- */
/*      Intercept DROP TABLE                                            */
/* -------------------------------------------------------------------- */
    if( STARTS_WITH_CI(osSQLCommand, "DROP TABLE ") )
    {
        const char *pszLayerName = osSQLCommand.c_str() + strlen("DROP TABLE ");

        while( *pszLayerName == ' ' )
            pszLayerName++;

        if( DeleteVectorOrRasterLayer(SQLUnescape(pszLayerName)) )
            return nullptr;
    }

/* -------------------------------------------------------------------- */
/*      Intercept ALTER TABLE ... RENAME TO                             */
/* -------------------------------------------------------------------- */
    if( STARTS_WITH_CI(osSQLCommand, "ALTER TABLE ") )
    {
        char **papszTokens = SQLTokenize( osSQLCommand );
        /* ALTER TABLE src_table RENAME TO dst_table */
        if( CSLCount(papszTokens) == 6 && EQUAL(papszTokens[3], "RENAME") &&
            EQUAL(papszTokens[4], "TO") )
        {
            const char* pszSrcTableName = papszTokens[2];
            const char* pszDstTableName = papszTokens[5];
            OGRGeoPackageTableLayer* poSrcLayer =
                (OGRGeoPackageTableLayer*)GetLayerByName(
                        SQLUnescape(pszSrcTableName));
            if( poSrcLayer )
            {
                poSrcLayer->RenameTo( SQLUnescape(pszDstTableName) );
                CSLDestroy(papszTokens);
                return nullptr;
            }
        }
        CSLDestroy(papszTokens);
    }

    if( EQUAL(osSQLCommand, "VACUUM") )
    {
        ResetReadingAllLayers();
    }

    if( EQUAL(osSQLCommand, "BEGIN") )
    {
        SoftStartTransaction();
        return nullptr;
    }
    else if( EQUAL(osSQLCommand, "COMMIT") )
    {
        SoftCommitTransaction();
        return nullptr;
    }
    else if( EQUAL(osSQLCommand, "ROLLBACK") )
    {
        SoftRollbackTransaction();
        return nullptr;
    }

    if( pszDialect != nullptr && EQUAL(pszDialect,"OGRSQL") )
        return GDALDataset::ExecuteSQL( osSQLCommand,
                                          poSpatialFilter,
                                          pszDialect );
    else if( pszDialect != nullptr && EQUAL(pszDialect,"INDIRECT_SQLITE") )
        return GDALDataset::ExecuteSQL( osSQLCommand,
                                          poSpatialFilter,
                                          "SQLITE" );

#if SQLITE_VERSION_NUMBER < 3007017
    // Emulate PRAGMA application_id
    if( EQUAL(osSQLCommand, "PRAGMA application_id") )
    {
        return new OGRSQLiteSingleFeatureLayer
                                ( osSQLCommand.c_str() + 7, m_nApplicationId );
    }
#endif

/* -------------------------------------------------------------------- */
/*      Prepare statement.                                              */
/* -------------------------------------------------------------------- */
    sqlite3_stmt *hSQLStmt = nullptr;

    /* This will speed-up layer creation */
    /* ORDER BY are costly to evaluate and are not necessary to establish */
    /* the layer definition. */
    bool bUseStatementForGetNextFeature = true;
    bool bEmptyLayer = false;
    CPLString osSQLCommandTruncated(osSQLCommand);

    if( osSQLCommand.ifind("SELECT ") == 0 &&
        CPLString(osSQLCommand.substr(1)).ifind("SELECT ") == std::string::npos &&
        osSQLCommand.ifind(" UNION ") == std::string::npos &&
        osSQLCommand.ifind(" INTERSECT ") == std::string::npos &&
        osSQLCommand.ifind(" EXCEPT ") == std::string::npos )
    {
        size_t nOrderByPos = osSQLCommand.ifind(" ORDER BY ");
        if( nOrderByPos != std::string::npos )
        {
            osSQLCommandTruncated.resize(nOrderByPos);
            bUseStatementForGetNextFeature = false;
        }
    }

    int rc = sqlite3_prepare_v2( hDB, osSQLCommandTruncated.c_str(),
                              static_cast<int>(osSQLCommandTruncated.size()),
                              &hSQLStmt, nullptr );

    if( rc != SQLITE_OK )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                "In ExecuteSQL(): sqlite3_prepare_v2(%s):\n  %s",
                osSQLCommandTruncated.c_str(), sqlite3_errmsg(hDB) );

        if( hSQLStmt != nullptr )
        {
            sqlite3_finalize( hSQLStmt );
        }

        return nullptr;
    }

/* -------------------------------------------------------------------- */
/*      Do we get a resultset?                                          */
/* -------------------------------------------------------------------- */
    rc = sqlite3_step( hSQLStmt );
    if( rc != SQLITE_ROW )
    {
        if ( rc != SQLITE_DONE )
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                  "In ExecuteSQL(): sqlite3_step(%s):\n  %s",
                  osSQLCommandTruncated.c_str(), sqlite3_errmsg(hDB) );

            sqlite3_finalize( hSQLStmt );
            return nullptr;
        }

        if( EQUAL(osSQLCommand, "VACUUM") )
        {
            sqlite3_finalize( hSQLStmt );
            /* VACUUM rewrites the DB, so we need to reset the application id */
            SetApplicationAndUserVersionId();
            return nullptr;
        }

        if( !STARTS_WITH_CI(osSQLCommand, "SELECT ") )
        {
            sqlite3_finalize( hSQLStmt );
            return nullptr;
        }

        bUseStatementForGetNextFeature = false;
        bEmptyLayer = true;
    }

/* -------------------------------------------------------------------- */
/*      Special case for some functions which must be run               */
/*      only once                                                       */
/* -------------------------------------------------------------------- */
    if( STARTS_WITH_CI(osSQLCommand, "SELECT ") )
    {
        for( unsigned int i=0; i < sizeof(apszFuncsWithSideEffects) /
               sizeof(apszFuncsWithSideEffects[0]); i++ )
        {
            if( EQUALN(apszFuncsWithSideEffects[i], osSQLCommand.c_str() + 7,
                       strlen(apszFuncsWithSideEffects[i])) )
            {
                if (sqlite3_column_count( hSQLStmt ) == 1 &&
                    sqlite3_column_type( hSQLStmt, 0 ) == SQLITE_INTEGER )
                {
                    int ret = sqlite3_column_int( hSQLStmt, 0 );

                    sqlite3_finalize( hSQLStmt );

                    return new OGRSQLiteSingleFeatureLayer
                                        ( apszFuncsWithSideEffects[i], ret );
                }
            }
        }
    }
    else if( STARTS_WITH_CI(osSQLCommand, "PRAGMA ") )
    {
        if (sqlite3_column_count( hSQLStmt ) == 1 &&
            sqlite3_column_type( hSQLStmt, 0 ) == SQLITE_INTEGER )
        {
            int ret = sqlite3_column_int( hSQLStmt, 0 );

            sqlite3_finalize( hSQLStmt );

            return new OGRSQLiteSingleFeatureLayer
                                ( osSQLCommand.c_str() + 7, ret );
        }
        else if (sqlite3_column_count( hSQLStmt ) == 1 &&
                 sqlite3_column_type( hSQLStmt, 0 ) == SQLITE_TEXT )
        {
            const char* pszRet = (const char*) sqlite3_column_text( hSQLStmt, 0 );

            OGRLayer* poRet = new OGRSQLiteSingleFeatureLayer
                                ( osSQLCommand.c_str() + 7, pszRet );

            sqlite3_finalize( hSQLStmt );

            return poRet;
        }
    }

/* -------------------------------------------------------------------- */
/*      Create layer.                                                   */
/* -------------------------------------------------------------------- */

    CPLString osSQL = osSQLCommand;
    OGRLayer* poLayer = new OGRGeoPackageSelectLayer(
        this, osSQL, hSQLStmt,
        bUseStatementForGetNextFeature, bEmptyLayer );

    if( poSpatialFilter != nullptr && poLayer->GetLayerDefn()->GetGeomFieldCount() > 0 )
        poLayer->SetSpatialFilter( 0, poSpatialFilter );

    return poLayer;
}

/************************************************************************/
/*                          ReleaseResultSet()                          */
/************************************************************************/

void GDALGeoPackageDataset::ReleaseResultSet( OGRLayer * poLayer )

{
    delete poLayer;
}

/************************************************************************/
/*                         HasExtensionsTable()                         */
/************************************************************************/

bool GDALGeoPackageDataset::HasExtensionsTable()
{
    return SQLGetInteger(hDB,
        "SELECT 1 FROM sqlite_master WHERE name = 'gpkg_extensions' "
        "AND type IN ('table', 'view')", nullptr) == 1;
}

/************************************************************************/
/*                    CheckUnknownExtensions()                          */
/************************************************************************/

void GDALGeoPackageDataset::CheckUnknownExtensions(bool bCheckRasterTable)
{
    if( !HasExtensionsTable() )
        return;

    char* pszSQL = nullptr;
    if( !bCheckRasterTable)
        pszSQL = sqlite3_mprintf(
            "SELECT extension_name, definition, scope FROM gpkg_extensions "
            "WHERE (table_name IS NULL "
            "AND extension_name IS NOT NULL "
            "AND definition IS NOT NULL "
            "AND scope IS NOT NULL "
            "AND extension_name NOT IN ("
            "'gdal_aspatial', "
            "'gpkg_elevation_tiles', " // Old name before GPKG 1.2 approval
            "'2d_gridded_coverage', " // Old name after GPKG 1.2 and before OGC 17-066r1 finalization
            "'gpkg_2d_gridded_coverage', " // Name in OGC 17-066r1 final
            "'gpkg_metadata', "
            "'gpkg_schema', "
            "'gpkg_crs_wkt')) "
#ifdef WORKAROUND_SQLITE3_BUGS
            "OR 0 "
#endif
            "LIMIT 1000"
        );
    else
        pszSQL = sqlite3_mprintf(
            "SELECT extension_name, definition, scope FROM gpkg_extensions "
            "WHERE (lower(table_name) = lower('%q') "
            "AND extension_name IS NOT NULL "
            "AND definition IS NOT NULL "
            "AND scope IS NOT NULL "
            "AND extension_name NOT IN ("
            "'gpkg_elevation_tiles', " // Old name before GPKG 1.2 approval
            "'2d_gridded_coverage', " // Old name after GPKG 1.2 and before OGC 17-066r1 finalization
            "'gpkg_2d_gridded_coverage', " // Name in OGC 17-066r1 final
            "'gpkg_metadata', "
            "'gpkg_schema', "
            "'gpkg_crs_wkt')) "
#ifdef WORKAROUND_SQLITE3_BUGS
            "OR 0 "
#endif
            "LIMIT 1000"
            ,
            m_osRasterTable.c_str());

    SQLResult oResultTable;
    OGRErr err = SQLQuery(GetDB(), pszSQL, &oResultTable);
    sqlite3_free(pszSQL);
    if ( err == OGRERR_NONE && oResultTable.nRowCount > 0 )
    {
        for(int i=0; i<oResultTable.nRowCount;i++)
        {
            const char* pszExtName = SQLResultGetValue(&oResultTable, 0, i);
            const char* pszDefinition = SQLResultGetValue(&oResultTable, 1, i);
            const char* pszScope = SQLResultGetValue(&oResultTable, 2, i);

            if( EQUAL(pszExtName, "gpkg_webp") )
            {
                if( GDALGetDriverByName("WEBP") == nullptr )
                {
                    CPLError(CE_Warning, CPLE_AppDefined,
                             "Table %s contains WEBP tiles, but GDAL configured "
                             "without WEBP support. Data will be missing",
                             m_osRasterTable.c_str());
                }
                m_eTF = GPKG_TF_WEBP;
                continue;
            }
            if( EQUAL(pszExtName, "gpkg_zoom_other") )
            {
                m_bZoomOther = true;
                continue;
            }

            if( GetUpdate() && EQUAL(pszScope, "write-only") )
            {
                CPLError(CE_Warning, CPLE_AppDefined,
                         "Database relies on the '%s' (%s) extension that should "
                         "be implemented for safe write-support, but is not currently. "
                         "Update of that database are strongly discouraged to avoid corruption.",
                         pszExtName, pszDefinition);
            }
            else if( GetUpdate() && EQUAL(pszScope, "read-write") )
            {
                CPLError(CE_Warning, CPLE_AppDefined,
                         "Database relies on the '%s' (%s) extension that should "
                         "be implemented in order to read/write it safely, but is not currently. "
                         "Some data may be missing while reading that database, and updates are strongly discouraged.",
                         pszExtName, pszDefinition);
            }
            else if( EQUAL(pszScope, "read-write") )
            {
                CPLError(CE_Warning, CPLE_AppDefined,
                         "Database relies on the '%s' (%s) extension that should "
                         "be implemented in order to read it safely, but is not currently. "
                         "Some data may be missing while reading that database.",
                         pszExtName, pszDefinition);
            }
        }
    }
    SQLResultFree(&oResultTable);
}

/************************************************************************/
/*                         HasGDALAspatialExtension()                       */
/************************************************************************/

bool GDALGeoPackageDataset::HasGDALAspatialExtension()
{
    if (!HasExtensionsTable())
        return false;

    SQLResult oResultTable;
    OGRErr err = SQLQuery(hDB,
        "SELECT * FROM gpkg_extensions "
        "WHERE (extension_name = 'gdal_aspatial' "
        "AND table_name IS NULL "
        "AND column_name IS NULL)"
#ifdef WORKAROUND_SQLITE3_BUGS
        " OR 0"
#endif
        , &oResultTable);
    bool bHasExtension = ( err == OGRERR_NONE && oResultTable.nRowCount == 1 );
    SQLResultFree(&oResultTable);
    return bHasExtension;
}

/************************************************************************/
/*                  CreateGDALAspatialExtension()                       */
/************************************************************************/

OGRErr GDALGeoPackageDataset::CreateGDALAspatialExtension()
{
    if( CreateExtensionsTableIfNecessary() != OGRERR_NONE )
        return OGRERR_FAILURE;

    if( HasGDALAspatialExtension() )
        return OGRERR_NONE;

    const char* pszCreateAspatialExtension =
        "INSERT INTO gpkg_extensions "
        "(table_name, column_name, extension_name, definition, scope) "
        "VALUES "
        "(NULL, NULL, 'gdal_aspatial', 'http://gdal.org/geopackage_aspatial.html', 'read-write')";

    return SQLCommand(hDB, pszCreateAspatialExtension);
}

/************************************************************************/
/*                  CreateExtensionsTableIfNecessary()                  */
/************************************************************************/

OGRErr GDALGeoPackageDataset::CreateExtensionsTableIfNecessary()
{
    /* Check if the table gpkg_extensions exists */
    if( HasExtensionsTable() )
        return OGRERR_NONE;

    /* Requirement 79 : Every extension of a GeoPackage SHALL be registered */
    /* in a corresponding row in the gpkg_extensions table. The absence of a */
    /* gpkg_extensions table or the absence of rows in gpkg_extensions table */
    /* SHALL both indicate the absence of extensions to a GeoPackage. */
    const char* pszCreateGpkgExtensions =
        "CREATE TABLE gpkg_extensions ("
        "table_name TEXT,"
        "column_name TEXT,"
        "extension_name TEXT NOT NULL,"
        "definition TEXT NOT NULL,"
        "scope TEXT NOT NULL,"
        "CONSTRAINT ge_tce UNIQUE (table_name, column_name, extension_name)"
        ")";

    return SQLCommand(hDB, pszCreateGpkgExtensions);
}

/************************************************************************/
/*                     OGRGeoPackageGetHeader()                         */
/************************************************************************/

static bool OGRGeoPackageGetHeader( sqlite3_context* pContext,
                                    int /*argc*/,
                                    sqlite3_value** argv,
                                    GPkgHeader* psHeader,
                                    bool bNeedExtent )
{
    if( sqlite3_value_type (argv[0]) != SQLITE_BLOB )
    {
        sqlite3_result_null(pContext);
        return false;
    }
    int nBLOBLen = sqlite3_value_bytes (argv[0]);
    const GByte* pabyBLOB = (const GByte *) sqlite3_value_blob (argv[0]);

    if( nBLOBLen < 8 ||
        GPkgHeaderFromWKB(pabyBLOB, nBLOBLen, psHeader) != OGRERR_NONE )
    {
        bool bEmpty = false;
        memset( psHeader, 0, sizeof(*psHeader) );
        if( OGRSQLiteLayer::GetSpatialiteGeometryHeader(
                                        pabyBLOB, nBLOBLen,
                                        &(psHeader->iSrsId),
                                        nullptr,
                                        &bEmpty,
                                        &(psHeader->MinX),
                                        &(psHeader->MinY),
                                        &(psHeader->MaxX),
                                        &(psHeader->MaxY) ) == OGRERR_NONE )
        {
            psHeader->bEmpty = bEmpty;
            if( !(bEmpty && bNeedExtent) )
                return true;
        }

        sqlite3_result_null(pContext);
        return false;
    }

    if( psHeader->bEmpty && bNeedExtent )
    {
        sqlite3_result_null(pContext);
        return false;
    }
    else if( !(psHeader->bExtentHasXY) && bNeedExtent )
    {
        OGRGeometry *poGeom = GPkgGeometryToOGR(pabyBLOB, nBLOBLen, nullptr);
        if( poGeom == nullptr || poGeom->IsEmpty() )
        {
            sqlite3_result_null(pContext);
            delete poGeom;
            return false;
        }
        OGREnvelope sEnvelope;
        poGeom->getEnvelope(&sEnvelope);
        psHeader->MinX = sEnvelope.MinX;
        psHeader->MaxX = sEnvelope.MaxX;
        psHeader->MinY = sEnvelope.MinY;
        psHeader->MaxY = sEnvelope.MaxY;
        delete poGeom;
    }
    return true;
}

/************************************************************************/
/*                      OGRGeoPackageSTMinX()                           */
/************************************************************************/

static
void OGRGeoPackageSTMinX(sqlite3_context* pContext,
                        int argc, sqlite3_value** argv)
{
    GPkgHeader sHeader;
    if( !OGRGeoPackageGetHeader(pContext, argc, argv, &sHeader, true) )
        return;
    sqlite3_result_double( pContext, sHeader.MinX );
}

/************************************************************************/
/*                      OGRGeoPackageSTMinY()                           */
/************************************************************************/

static
void OGRGeoPackageSTMinY(sqlite3_context* pContext,
                        int argc, sqlite3_value** argv)
{
    GPkgHeader sHeader;
    if( !OGRGeoPackageGetHeader(pContext, argc, argv, &sHeader, true) )
        return;
    sqlite3_result_double( pContext, sHeader.MinY );
}

/************************************************************************/
/*                      OGRGeoPackageSTMaxX()                           */
/************************************************************************/

static
void OGRGeoPackageSTMaxX(sqlite3_context* pContext,
                        int argc, sqlite3_value** argv)
{
    GPkgHeader sHeader;
    if( !OGRGeoPackageGetHeader(pContext, argc, argv, &sHeader, true) )
        return;
    sqlite3_result_double( pContext, sHeader.MaxX );
}

/************************************************************************/
/*                      OGRGeoPackageSTMaxY()                           */
/************************************************************************/

static
void OGRGeoPackageSTMaxY(sqlite3_context* pContext,
                        int argc, sqlite3_value** argv)
{
    GPkgHeader sHeader;
    if( !OGRGeoPackageGetHeader(pContext, argc, argv, &sHeader, true) )
        return;
    sqlite3_result_double( pContext, sHeader.MaxY );
}

/************************************************************************/
/*                     OGRGeoPackageSTIsEmpty()                         */
/************************************************************************/

static
void OGRGeoPackageSTIsEmpty(sqlite3_context* pContext,
                        int argc, sqlite3_value** argv)
{
    GPkgHeader sHeader;
    if( !OGRGeoPackageGetHeader(pContext, argc, argv, &sHeader, false) )
        return;
    sqlite3_result_int( pContext, sHeader.bEmpty );
}

/************************************************************************/
/*                    OGRGeoPackageSTGeometryType()                     */
/************************************************************************/

static
void OGRGeoPackageSTGeometryType(sqlite3_context* pContext,
                                 int /*argc*/, sqlite3_value** argv)
{
    GPkgHeader sHeader;

    int nBLOBLen = sqlite3_value_bytes (argv[0]);
    const GByte* pabyBLOB = (const GByte *) sqlite3_value_blob (argv[0]);
    OGRwkbGeometryType eGeometryType;

    if( nBLOBLen < 8 ||
        GPkgHeaderFromWKB(pabyBLOB, nBLOBLen, &sHeader) != OGRERR_NONE )
    {
        if( OGRSQLiteLayer::GetSpatialiteGeometryHeader(
                                        pabyBLOB, nBLOBLen,
                                        nullptr,
                                        &eGeometryType,
                                        nullptr,
                                        nullptr,
                                        nullptr,
                                        nullptr,
                                        nullptr ) == OGRERR_NONE )
        {
            sqlite3_result_text( pContext,
                                 OGRToOGCGeomType(eGeometryType),
                                 -1, SQLITE_TRANSIENT );
            return;
        }
        else
        {
            sqlite3_result_null( pContext );
            return;
        }
    }

    if( static_cast<size_t>(nBLOBLen) < sHeader.nHeaderLen + 5 )
    {
        sqlite3_result_null( pContext );
        return;
    }

    OGRErr err = OGRReadWKBGeometryType( (GByte*)pabyBLOB + sHeader.nHeaderLen,
                                         wkbVariantIso, &eGeometryType );
    if( err != OGRERR_NONE )
        sqlite3_result_null( pContext );
    else
        sqlite3_result_text( pContext, OGRToOGCGeomType(eGeometryType), -1, SQLITE_TRANSIENT );
}

/************************************************************************/
/*                    OGRGeoPackageGPKGIsAssignable()                   */
/************************************************************************/

static
void OGRGeoPackageGPKGIsAssignable(sqlite3_context* pContext,
                                   int /*argc*/,
                                   sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_TEXT ||
        sqlite3_value_type (argv[1]) != SQLITE_TEXT )
    {
        sqlite3_result_int( pContext, 0 );
        return;
    }

    const char* pszExpected = (const char*)sqlite3_value_text(argv[0]);
    const char* pszActual = (const char*)sqlite3_value_text(argv[1]);
    int bIsAssignable = OGR_GT_IsSubClassOf( OGRFromOGCGeomType(pszActual),
                                             OGRFromOGCGeomType(pszExpected) );
    sqlite3_result_int( pContext, bIsAssignable );
}

/************************************************************************/
/*                     OGRGeoPackageSTSRID()                            */
/************************************************************************/

static
void OGRGeoPackageSTSRID(sqlite3_context* pContext,
                        int argc, sqlite3_value** argv)
{
    GPkgHeader sHeader;
    if( !OGRGeoPackageGetHeader(pContext, argc, argv, &sHeader, false) )
        return;
    sqlite3_result_int( pContext, sHeader.iSrsId );
}

/************************************************************************/
/*                      OGRGeoPackageTransform()                        */
/************************************************************************/

static
void OGRGeoPackageTransform(sqlite3_context* pContext,
                            int argc,
                            sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_BLOB ||
        sqlite3_value_type (argv[1]) != SQLITE_INTEGER )
    {
        sqlite3_result_blob(pContext, nullptr, 0, nullptr);
        return;
    }

    const int nBLOBLen = sqlite3_value_bytes (argv[0]);
    const GByte* pabyBLOB =
                reinterpret_cast<const GByte*>(sqlite3_value_blob (argv[0]));
    GPkgHeader sHeader;
    if( !OGRGeoPackageGetHeader( pContext, argc, argv, &sHeader, false) )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid geometry");
        sqlite3_result_blob(pContext, nullptr, 0, nullptr);
        return;
    }

    GDALGeoPackageDataset* poDS = static_cast<GDALGeoPackageDataset*>(
                                                sqlite3_user_data(pContext));

    OGRSpatialReference* poSrcSRS = poDS->GetSpatialRef(sHeader.iSrsId);
    if( poSrcSRS == nullptr )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "SRID set on geometry (%d) is invalid", sHeader.iSrsId);
        sqlite3_result_blob(pContext, nullptr, 0, nullptr);
        return;
    }

    int nDestSRID = sqlite3_value_int (argv[1]);
    OGRSpatialReference* poDstSRS = poDS->GetSpatialRef(nDestSRID);
    if( poDstSRS == nullptr )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Target SRID (%d) is invalid", nDestSRID);
        sqlite3_result_blob(pContext, nullptr, 0, nullptr);
        poSrcSRS->Release();
        return;
    }

    OGRGeometry* poGeom = GPkgGeometryToOGR(pabyBLOB, nBLOBLen, nullptr);
    if( poGeom == nullptr )
    {
        // Try also spatialite geometry blobs
        if( OGRSQLiteLayer::ImportSpatiaLiteGeometry( pabyBLOB, nBLOBLen,
                                                    &poGeom ) != OGRERR_NONE )
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Invalid geometry");
            sqlite3_result_blob(pContext, nullptr, 0, nullptr);
            poSrcSRS->Release();
            poDstSRS->Release();
            return;
        }
    }

    poGeom->assignSpatialReference(poSrcSRS);
    if( poGeom->transformTo(poDstSRS) != OGRERR_NONE )
    {
        sqlite3_result_blob(pContext, nullptr, 0, nullptr);
        poSrcSRS->Release();
        poDstSRS->Release();
        return;
    }

    size_t nBLOBDestLen = 0;
    GByte* pabyDestBLOB =
                    GPkgGeometryFromOGR(poGeom, nDestSRID, &nBLOBDestLen);
    sqlite3_result_blob(pContext, pabyDestBLOB,
                        static_cast<int>(nBLOBDestLen), VSIFree);

    poSrcSRS->Release();
    poDstSRS->Release();
    delete poGeom;
}

/************************************************************************/
/*                      OGRGeoPackageSridFromAuthCRS()                  */
/************************************************************************/

static
void OGRGeoPackageSridFromAuthCRS(sqlite3_context* pContext,
                                  int /*argc*/,
                                  sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_TEXT ||
        sqlite3_value_type (argv[1]) != SQLITE_INTEGER )
    {
        sqlite3_result_int(pContext, -1);
        return;
    }

    GDALGeoPackageDataset* poDS =
            static_cast<GDALGeoPackageDataset*>(sqlite3_user_data(pContext));

    char* pszSQL = sqlite3_mprintf(
        "SELECT srs_id FROM gpkg_spatial_ref_sys WHERE "
        "lower(organization) = lower('%q') AND organization_coordsys_id = %d",
        sqlite3_value_text( argv[0] ),
        sqlite3_value_int( argv[1] ) );
    OGRErr err = OGRERR_NONE;
    int nSRSId = SQLGetInteger(poDS->GetDB(), pszSQL, &err);
    sqlite3_free(pszSQL);
    if( err != OGRERR_NONE )
        nSRSId = -1;
    sqlite3_result_int(pContext, nSRSId);
}

/************************************************************************/
/*                    OGRGeoPackageImportFromEPSG()                     */
/************************************************************************/

static
void OGRGeoPackageImportFromEPSG(sqlite3_context* pContext,
                                     int /*argc*/,
                                     sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_INTEGER )
    {
        sqlite3_result_int( pContext, -1 );
        return;
    }

    GDALGeoPackageDataset* poDS =
            static_cast<GDALGeoPackageDataset*>(sqlite3_user_data(pContext));
    OGRSpatialReference oSRS;
    if( oSRS.importFromEPSG( sqlite3_value_int( argv[0] ) ) != OGRERR_NONE )
    {
        sqlite3_result_int( pContext, -1 );
        return;
    }

    sqlite3_result_int( pContext,poDS->GetSrsId(oSRS) );
}

/************************************************************************/
/*                  OGRGeoPackageCreateSpatialIndex()                   */
/************************************************************************/

static
void OGRGeoPackageCreateSpatialIndex(sqlite3_context* pContext,
                                     int /*argc*/,
                                     sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_TEXT ||
        sqlite3_value_type (argv[1]) != SQLITE_TEXT )
    {
        sqlite3_result_int( pContext, 0 );
        return;
    }

    const char* pszTableName = (const char*)sqlite3_value_text(argv[0]);
    const char* pszGeomName = (const char*)sqlite3_value_text(argv[1]);
    GDALGeoPackageDataset* poDS = (GDALGeoPackageDataset* )sqlite3_user_data(pContext);

    OGRGeoPackageTableLayer* poLyr = (OGRGeoPackageTableLayer*)poDS->GetLayerByName(pszTableName);
    if( poLyr == nullptr )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Unknown layer name");
        sqlite3_result_int( pContext, 0 );
        return;
    }
    if( !EQUAL(poLyr->GetGeometryColumn(), pszGeomName) )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Unknown geometry column name");
        sqlite3_result_int( pContext, 0 );
        return;
    }

    sqlite3_result_int( pContext, poLyr->CreateSpatialIndex() );
}

/************************************************************************/
/*                  OGRGeoPackageDisableSpatialIndex()                  */
/************************************************************************/

static
void OGRGeoPackageDisableSpatialIndex(sqlite3_context* pContext,
                                      int /*argc*/,
                                      sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_TEXT ||
        sqlite3_value_type (argv[1]) != SQLITE_TEXT )
    {
        sqlite3_result_int( pContext, 0 );
        return;
    }

    const char* pszTableName = (const char*)sqlite3_value_text(argv[0]);
    const char* pszGeomName = (const char*)sqlite3_value_text(argv[1]);
    GDALGeoPackageDataset* poDS = (GDALGeoPackageDataset* )sqlite3_user_data(pContext);

    OGRGeoPackageTableLayer* poLyr = (OGRGeoPackageTableLayer*)poDS->GetLayerByName(pszTableName);
    if( poLyr == nullptr )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Unknown layer name");
        sqlite3_result_int( pContext, 0 );
        return;
    }
    if( !EQUAL(poLyr->GetGeometryColumn(), pszGeomName) )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Unknown geometry column name");
        sqlite3_result_int( pContext, 0 );
        return;
    }

    sqlite3_result_int( pContext, poLyr->DropSpatialIndex(true) );
}

/************************************************************************/
/*                  OGRGeoPackageHasSpatialIndex()                      */
/************************************************************************/

static
void OGRGeoPackageHasSpatialIndex(sqlite3_context* pContext,
                                  int /*argc*/,
                                  sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_TEXT ||
        sqlite3_value_type (argv[1]) != SQLITE_TEXT )
    {
        sqlite3_result_int( pContext, 0 );
        return;
    }

    const char* pszTableName = (const char*)sqlite3_value_text(argv[0]);
    const char* pszGeomName = (const char*)sqlite3_value_text(argv[1]);
    GDALGeoPackageDataset* poDS = (GDALGeoPackageDataset* )sqlite3_user_data(pContext);

    OGRGeoPackageTableLayer* poLyr = (OGRGeoPackageTableLayer*)poDS->GetLayerByName(pszTableName);
    if( poLyr == nullptr )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Unknown layer name");
        sqlite3_result_int( pContext, 0 );
        return;
    }
    if( !EQUAL(poLyr->GetGeometryColumn(), pszGeomName) )
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Unknown geometry column name");
        sqlite3_result_int( pContext, 0 );
        return;
    }

    poLyr->RunDeferredCreationIfNecessary();
    poLyr->CreateSpatialIndexIfNecessary();

    sqlite3_result_int( pContext, poLyr->HasSpatialIndex() );
}

/************************************************************************/
/*                       GPKG_hstore_get_value()                        */
/************************************************************************/

static
void GPKG_hstore_get_value(sqlite3_context* pContext,
                           int /*argc*/,
                           sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_TEXT ||
        sqlite3_value_type (argv[1]) != SQLITE_TEXT )
    {
        sqlite3_result_null (pContext);
        return;
    }

    const char* pszHStore = (const char*)sqlite3_value_text(argv[0]);
    const char* pszSearchedKey = (const char*)sqlite3_value_text(argv[1]);
    char* pszValue = OGRHStoreGetValue(pszHStore, pszSearchedKey);
    if( pszValue != nullptr )
        sqlite3_result_text( pContext, pszValue, -1, CPLFree );
    else
        sqlite3_result_null( pContext );
}

/************************************************************************/
/*                      GPKG_GDAL_GetMemFileFromBlob()                  */
/************************************************************************/

static CPLString GPKG_GDAL_GetMemFileFromBlob(sqlite3_value** argv)
{
    int nBytes = sqlite3_value_bytes (argv[0]);
    const GByte* pabyBLOB = (const GByte *) sqlite3_value_blob (argv[0]);
    CPLString osMemFileName;
    osMemFileName.Printf("/vsimem/GPKG_GDAL_GetMemFileFromBlob_%p", argv);
    VSILFILE * fp = VSIFileFromMemBuffer( osMemFileName.c_str(),
                                          (GByte*)pabyBLOB,
                                          nBytes, FALSE);
    VSIFCloseL(fp);
    return osMemFileName;
}

/************************************************************************/
/*                       GPKG_GDAL_GetMimeType()                        */
/************************************************************************/

static
void GPKG_GDAL_GetMimeType(sqlite3_context* pContext,
                           int /*argc*/,
                           sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_BLOB )
    {
        sqlite3_result_null (pContext);
        return;
    }

    CPLString osMemFileName(GPKG_GDAL_GetMemFileFromBlob(argv));
    GDALDriver* poDriver = (GDALDriver*)GDALIdentifyDriver(osMemFileName, nullptr);
    if( poDriver != nullptr )
    {
        const char* pszRes = nullptr;
        if( EQUAL(poDriver->GetDescription(), "PNG") )
            pszRes = "image/png";
        else if( EQUAL(poDriver->GetDescription(), "JPEG") )
            pszRes = "image/jpeg";
        else if( EQUAL(poDriver->GetDescription(), "WEBP") )
            pszRes = "image/x-webp";
        else if( EQUAL(poDriver->GetDescription(), "GTIFF") )
            pszRes = "image/tiff";
        else
            pszRes = CPLSPrintf("gdal/%s", poDriver->GetDescription());
        sqlite3_result_text( pContext, pszRes, -1, SQLITE_TRANSIENT );
    }
    else
        sqlite3_result_null (pContext);
    VSIUnlink(osMemFileName);
}

/************************************************************************/
/*                       GPKG_GDAL_GetBandCount()                       */
/************************************************************************/

static
void GPKG_GDAL_GetBandCount(sqlite3_context* pContext,
                           int /*argc*/,
                           sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_BLOB )
    {
        sqlite3_result_null (pContext);
        return;
    }

    CPLString osMemFileName(GPKG_GDAL_GetMemFileFromBlob(argv));
    GDALDataset* poDS = (GDALDataset*) GDALOpenEx(osMemFileName,
                                                  GDAL_OF_RASTER | GDAL_OF_INTERNAL,
                                                  nullptr, nullptr, nullptr);
    if( poDS != nullptr )
    {
        sqlite3_result_int( pContext, poDS->GetRasterCount() );
        GDALClose( poDS );
    }
    else
        sqlite3_result_null (pContext);
    VSIUnlink(osMemFileName);
}

/************************************************************************/
/*                       GPKG_GDAL_HasColorTable()                      */
/************************************************************************/

static
void GPKG_GDAL_HasColorTable(sqlite3_context* pContext,
                             int /*argc*/,
                             sqlite3_value** argv)
{
    if( sqlite3_value_type (argv[0]) != SQLITE_BLOB )
    {
        sqlite3_result_null (pContext);
        return;
    }

    CPLString osMemFileName(GPKG_GDAL_GetMemFileFromBlob(argv));
    GDALDataset* poDS = (GDALDataset*) GDALOpenEx(osMemFileName,
                                                  GDAL_OF_RASTER | GDAL_OF_INTERNAL,
                                                  nullptr, nullptr, nullptr);
    if( poDS != nullptr )
    {
        sqlite3_result_int( pContext,
                            poDS->GetRasterCount() == 1 &&
                            poDS->GetRasterBand(1)->GetColorTable() != nullptr );
        GDALClose( poDS );
    }
    else
        sqlite3_result_null (pContext);
    VSIUnlink(osMemFileName);
}

/************************************************************************/
/*                      InstallSQLFunctions()                           */
/************************************************************************/

#ifndef SQLITE_DETERMINISTIC
#define SQLITE_DETERMINISTIC 0
#endif

void GDALGeoPackageDataset::InstallSQLFunctions()
{
#ifdef SPATIALITE_412_OR_LATER
    InitNewSpatialite();

    // Enable SpatiaLite 4.3 "amphibious" mode, i.e. that SpatiaLite functions
    // that take geometries will accept GPKG encoded geometries without
    // explicit conversion.
    // Use sqlite3_exec() instead of SQLCommand() since we don't want verbose
    // error.
    sqlite3_exec(hDB, "SELECT EnableGpkgAmphibiousMode()", nullptr, nullptr, nullptr);
#endif

    /* Used by RTree Spatial Index Extension */
    sqlite3_create_function(hDB, "ST_MinX", 1,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageSTMinX, nullptr, nullptr);
    sqlite3_create_function(hDB, "ST_MinY", 1,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageSTMinY, nullptr, nullptr);
    sqlite3_create_function(hDB, "ST_MaxX", 1,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageSTMaxX, nullptr, nullptr);
    sqlite3_create_function(hDB, "ST_MaxY", 1,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageSTMaxY, nullptr, nullptr);
    sqlite3_create_function(hDB, "ST_IsEmpty", 1,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageSTIsEmpty, nullptr, nullptr);

    /* Used by Geometry Type Triggers Extension */
    sqlite3_create_function(hDB, "ST_GeometryType", 1,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageSTGeometryType, nullptr, nullptr);
    sqlite3_create_function(hDB, "GPKG_IsAssignable", 2,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageGPKGIsAssignable, nullptr, nullptr);

    /* Used by Geometry SRS ID Triggers Extension */
    sqlite3_create_function(hDB, "ST_SRID", 1,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            OGRGeoPackageSTSRID, nullptr, nullptr);

    /* Spatialite-like functions */
    sqlite3_create_function(hDB, "CreateSpatialIndex", 2,
                            SQLITE_UTF8, this,
                            OGRGeoPackageCreateSpatialIndex, nullptr, nullptr);
    sqlite3_create_function(hDB, "DisableSpatialIndex", 2,
                            SQLITE_UTF8, this,
                            OGRGeoPackageDisableSpatialIndex, nullptr, nullptr);
    sqlite3_create_function(hDB, "HasSpatialIndex", 2, SQLITE_UTF8, this,
                            OGRGeoPackageHasSpatialIndex,
                            nullptr, nullptr);

    // HSTORE functions
    sqlite3_create_function(hDB, "hstore_get_value", 2,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                            GPKG_hstore_get_value, nullptr, nullptr);

    // Override a few Spatialite functions to work with gpkg_spatial_ref_sys
    sqlite3_create_function(hDB, "ST_Transform", 2,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, this,
                            OGRGeoPackageTransform, nullptr, nullptr);
    sqlite3_create_function(hDB, "Transform", 2,
                            SQLITE_UTF8 | SQLITE_DETERMINISTIC, this,
                            OGRGeoPackageTransform, nullptr, nullptr);
    sqlite3_create_function(hDB, "SridFromAuthCRS", 2,
                            SQLITE_UTF8, this,
                            OGRGeoPackageSridFromAuthCRS, nullptr, nullptr);

    // GDAL specific function
    sqlite3_create_function(hDB, "ImportFromEPSG", 1,
                            SQLITE_UTF8, this,
                            OGRGeoPackageImportFromEPSG, nullptr, nullptr);

    // Debug functions
    if( CPLTestBool(CPLGetConfigOption("GPKG_DEBUG", "FALSE")) )
    {
        sqlite3_create_function(hDB, "GDAL_GetMimeType", 1,
                                SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                                GPKG_GDAL_GetMimeType, nullptr, nullptr);
        sqlite3_create_function(hDB, "GDAL_GetBandCount", 1,
                                SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                                GPKG_GDAL_GetBandCount, nullptr, nullptr);
        sqlite3_create_function(hDB, "GDAL_HasColorTable", 1,
                                SQLITE_UTF8 | SQLITE_DETERMINISTIC, nullptr,
                                GPKG_GDAL_HasColorTable, nullptr, nullptr);
    }
}

/************************************************************************/
/*                         OpenOrCreateDB()                             */
/************************************************************************/

bool GDALGeoPackageDataset::OpenOrCreateDB(int flags)
{
    const bool bSuccess =
        CPL_TO_BOOL(OGRSQLiteBaseDataSource::OpenOrCreateDB(flags, FALSE));
    if( !bSuccess )
        return false;

    InstallSQLFunctions();

    return true;
}

/************************************************************************/
/*                   GetLayerWithGetSpatialWhereByName()                */
/************************************************************************/

std::pair<OGRLayer*, IOGRSQLiteGetSpatialWhere*>
    GDALGeoPackageDataset::GetLayerWithGetSpatialWhereByName( const char* pszName )
{
    OGRGeoPackageLayer* poRet = (OGRGeoPackageLayer*) GetLayerByName(pszName);
    return std::pair<OGRLayer*, IOGRSQLiteGetSpatialWhere*>(poRet, poRet);
}

/************************************************************************/
/*                         IsInTransaction()                            */
/************************************************************************/

bool GDALGeoPackageDataset::IsInTransaction() const
{
    return nSoftTransactionLevel > 0;
}

/************************************************************************/
/*                       CommitTransaction()                            */
/************************************************************************/

OGRErr GDALGeoPackageDataset::CommitTransaction()

{
    if( nSoftTransactionLevel == 1 )
    {
        FlushMetadata();
        for( int i = 0; i < m_nLayers; i++ )
        {
            m_papoLayers[i]->RunDeferredCreationIfNecessary();
        }
    }

    return OGRSQLiteBaseDataSource::CommitTransaction();
}

/************************************************************************/
/*                     RollbackTransaction()                            */
/************************************************************************/

OGRErr GDALGeoPackageDataset::RollbackTransaction()

{
#ifdef ENABLE_GPKG_OGR_CONTENTS
    std::vector<bool> abAddTriggers;
    std::vector<bool> abTriggersDeletedInTransaction;
#endif
    if( nSoftTransactionLevel == 1 )
    {
        FlushMetadata();
        for( int i = 0; i < m_nLayers; i++ )
        {
#ifdef ENABLE_GPKG_OGR_CONTENTS
            abAddTriggers.push_back(
                        m_papoLayers[i]->GetAddOGRFeatureCountTriggers());
            abTriggersDeletedInTransaction.push_back(
                m_papoLayers[i]->
                    GetOGRFeatureCountTriggersDeletedInTransaction());
            m_papoLayers[i]->SetAddOGRFeatureCountTriggers(false);
#endif
            m_papoLayers[i]->SyncToDisk();
            m_papoLayers[i]->ResetReading();
#ifdef ENABLE_GPKG_OGR_CONTENTS
            m_papoLayers[i]->DisableFeatureCount();
#endif
        }
    }

    OGRErr eErr = OGRSQLiteBaseDataSource::RollbackTransaction();
#ifdef ENABLE_GPKG_OGR_CONTENTS
    if( !abAddTriggers.empty() )
    {
        for( int i = 0; i < m_nLayers; i++ )
        {
            if( abTriggersDeletedInTransaction[i] )
            {
                m_papoLayers[i]->SetOGRFeatureCountTriggersEnabled(true);
            }
            else
            {
                m_papoLayers[i]->SetAddOGRFeatureCountTriggers(abAddTriggers[i]);
            }
        }
    }
#endif
    return eErr;
}

/************************************************************************/
/*                       GetGeometryTypeString()                        */
/************************************************************************/

const char* GDALGeoPackageDataset::GetGeometryTypeString(OGRwkbGeometryType eType)
{
    const char* pszGPKGGeomType = OGRToOGCGeomType(eType);
    if( EQUAL(pszGPKGGeomType, "GEOMETRYCOLLECTION") &&
        CPLTestBool(CPLGetConfigOption("OGR_GPKG_GEOMCOLLECTION", "NO")) )
    {
        pszGPKGGeomType = "GEOMCOLLECTION";
    }
    return pszGPKGGeomType;
}
