# `gdal vector pipeline`

Added in version 3.11.

Process a vector dataset.

## Synopsis

    Usage: gdal vector pipeline [OPTIONS] <PIPELINE>

    Process a vector dataset.

    Positional arguments:

    Common Options:
      -h, --help              Display help message and exit
      --json-usage            Display usage as JSON document and exit
      --config <KEY>=<VALUE>  Configuration option [may be repeated]
      --progress              Display progress bar

    <PIPELINE> is of the form: read|concat [READ-OPTIONS] ( ! <STEP-NAME> [STEP-OPTIONS] )* ! write [WRITE-OPTIONS]

A pipeline chains several steps, separated with the ! (exclamation mark) character. The first step must be `read` or `concat`, and the last one `write`. Each step has its own positional or non-positional arguments. Apart from `read`, `concat` and `write`, all other steps can potentially be used several times in a pipeline.

Potential steps are:

- read

    * read [OPTIONS] <INPUT>
    ------------------------

    Read a vector dataset.

    Positional arguments:
      -i, --input <INPUT>                       Input vector datasets [required]

    Options:
      -l, --layer, --input-layer <INPUT-LAYER>  Input layer name(s) [may be repeated]

    Advanced Options:
      --if, --input-format <INPUT-FORMAT>       Input formats [may be repeated]
      --oo, --open-option <KEY>=<VALUE>         Open options [may be repeated]

- concat

    * concat [OPTIONS] <INPUT>...
    -----------------------------

    Concatenate vector datasets.

    Positional arguments:
      -i, --input <INPUT>                                        Input vector datasets [1.. values] [required]

    Options:
      -l, --layer, --input-layer <INPUT-LAYER>                   Input layer name(s) [may be repeated]
      --mode <MODE>                                              Determine the strategy to create output layers from source layers . MODE=merge-per-layer-name|stack|single (default: merge-per-layer-name)
      --output-layer <OUTPUT-LAYER>                              Name of the output vector layer (single mode), or template to name the output vector layers (stack mode)
      --source-layer-field-name <SOURCE-LAYER-FIELD-NAME>        Name of the new field to add to contain identificoncation of the source layer, with value determined from 'source-layer-field-content'
      --source-layer-field-content <SOURCE-LAYER-FIELD-CONTENT>  A string, possibly using {AUTO_NAME}, {DS_NAME}, {DS_BASENAME}, {DS_INDEX}, {LAYER_NAME}, {LAYER_INDEX}
      --field-strategy <FIELD-STRATEGY>                          How to determine target fields from source fields. FIELD-STRATEGY=union|intersection (default: union)
      -s, --src-crs <SRC-CRS>                                    Source CRS
      -d, --dst-crs <DST-CRS>                                    Destination CRS

    Advanced Options:
      --if, --input-format <INPUT-FORMAT>                        Input formats [may be repeated]
      --oo, --open-option <KEY>=<VALUE>                          Open options [may be repeated]

Details for options can be found in gdal vector concat.

- clip

    * clip [OPTIONS]
    ----------------

    Clip a vector dataset.

    Options:
      --active-layer <ACTIVE-LAYER>    Set active layer (if not specified, all)
      --bbox <BBOX>                    Clipping bounding box as xmin,ymin,xmax,ymax
                                       Mutually exclusive with --geometry, --like
      --bbox-crs <BBOX-CRS>            CRS of clipping bounding box
      --geometry <GEOMETRY>            Clipping geometry (WKT or GeoJSON)
                                       Mutually exclusive with --bbox, --like
      --geometry-crs <GEOMETRY-CRS>    CRS of clipping geometry
      --like <DATASET>                 Dataset to use as a template for bounds
                                       Mutually exclusive with --bbox, --geometry
      --like-sql <SELECT-STATEMENT>    SELECT statement to run on the 'like' dataset
                                       Mutually exclusive with --like-where
      --like-layer <LAYER-NAME>        Name of the layer of the 'like' dataset
      --like-where <WHERE-EXPRESSION>  WHERE SQL clause to run on the 'like' dataset
                                       Mutually exclusive with --like-sql

Details for options can be found in gdal vector clip.

- edit

    * edit [OPTIONS]
    ----------------

    Edit metadata of a vector dataset.

    Options:
      --active-layer <ACTIVE-LAYER>    Set active layer (if not specified, all)
      --geometry-type <GEOMETRY-TYPE>  Layer geometry type
      --crs <CRS>                      Override CRS (without reprojection)
      --metadata <KEY>=<VALUE>         Add/update dataset metadata item [may be repeated]
      --unset-metadata <KEY>           Remove dataset metadata item [may be repeated]
      --layer-metadata <KEY>=<VALUE>   Add/update layer metadata item [may be repeated]
      --unset-layer-metadata <KEY>     Remove layer metadata item [may be repeated]

Details for options can be found in gdal vector edit.

- filter

    * filter [OPTIONS]
    ------------------

    Filter a vector dataset.

    Options:
      --active-layer <ACTIVE-LAYER>  Set active layer (if not specified, all)
      --bbox <BBOX>                  Bounding box as xmin,ymin,xmax,ymax
      --where <WHERE>|@<filename>    Attribute query in a restricted form of the queries used in the SQL WHERE statement

Details for options can be found in gdal vector filter.

- geom

    * geom <COMMAND> [OPTIONS]
    where <COMMAND> is one of:
      - buffer:              Compute a buffer around geometries of a vector dataset.
      - explode-collections: Explode geometries of type collection of a vector dataset.
      - make-valid:          Fix validity of geometries of a vector dataset.
      - segmentize:          Segmentize geometries of a vector dataset.
      - set-type:            Modify the geometry type of a vector dataset.
      - simplify:            Simplify geometries of a vector dataset.
      - swap-xy:             Swap X and Y coordinates of geometries of a vector dataset.

Details for options can be found in gdal vector geom.

- reproject

    * reproject [OPTIONS]
    ---------------------

    Reproject a vector dataset.

    Options:
      --active-layer <ACTIVE-LAYER>  Set active layer (if not specified, all)
      -s, --src-crs <SRC-CRS>        Source CRS
      -d, --dst-crs <DST-CRS>        Destination CRS [required]

Details for options can be found in gdal vector reproject.

- select

    * select [OPTIONS] <FIELDS>
    ---------------------------

    Select a subset of fields from a vector dataset.

    Positional arguments:
      --fields <FIELDS>              Fields to select (or exclude if --exclude) [may be repeated] [required]

    Options:
      --active-layer <ACTIVE-LAYER>  Set active layer (if not specified, all)
      --exclude                      Exclude specified fields
                                     Mutually exclusive with --ignore-missing-fields
      --ignore-missing-fields        Ignore missing fields
                                     Mutually exclusive with --exclude

Details for options can be found in gdal vector select.

- sql

    * sql [OPTIONS] <statement>|@<filename>
    ---------------------------------------

    Apply SQL statement(s) to a dataset.

    Positional arguments:
      --sql <statement>|@<filename>      SQL statement(s) [may be repeated] [required]

    Options:
      -l, --output-layer <OUTPUT-LAYER>  Output layer name(s) [may be repeated]
      --dialect <DIALECT>                SQL dialect (e.g. OGRSQL, SQLITE)

Details for options can be found in gdal vector sql.

- write

    * write [OPTIONS] <OUTPUT>
    --------------------------

    Write a vector dataset.

    Positional arguments:
      -o, --output <OUTPUT>                                Output vector dataset [required]

    Options:
      -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format ("GDALG" allowed)
      --co, --creation-option <KEY>=<VALUE>                Creation option [may be repeated]
      --lco, --layer-creation-option <KEY>=<VALUE>         Layer creation option [may be repeated]
      --overwrite                                          Whether overwriting existing output is allowed
      --update                                             Whether to open existing dataset in update mode
      --overwrite-layer                                    Whether overwriting existing layer is allowed
      --append                                             Whether appending to existing layer is allowed
      -l, --output-layer <OUTPUT-LAYER>                    Output layer name

## Description

gdal vector pipeline can be used to process a vector dataset and perform various processing steps.

## GDALG output (on-the-fly / streamed dataset)

A pipeline can be serialized as a JSON file using the `GDALG` output format. The resulting file can then be opened as a vector dataset using the GDALG: GDAL Streamed Algorithm driver, and apply the specified pipeline in a on-the-fly / streamed way.

The `command_line` member of the JSON file should nominally be the whole command line without the final `write` step, and is what is generated by `gdal vector pipeline ! .... ! write out.gdalg.json`.

    {
        "type": "gdal_streamed_alg",
        "command_line": "gdal vector pipeline ! read in.gpkg ! reproject --dst-crs=EPSG:32632"
    }

The final `write` step can be added but if so it must explicitly specify the `stream` output format and a non-significant output dataset name.

    {
        "type": "gdal_streamed_alg",
        "command_line": "gdal vector pipeline ! read in.gpkg ! reproject --dst-crs=EPSG:32632 ! write --output-format=streamed streamed_dataset"
    }

## Examples

### Example 1: Reproject a GeoPackage file to CRS EPSG:32632 ("WGS 84 / UTM zone 32N")

    $ gdal vector pipeline --progress ! read in.gpkg ! reproject --dst-crs=EPSG:32632 ! write out.gpkg --overwrite

### Example 2: Serialize the command of a reprojection of a GeoPackage file in a GDALG file, and later read it

    $ gdal vector pipeline --progress ! read in.gpkg ! reproject --dst-crs=EPSG:32632 ! write in_epsg_32632.gdalg.json --overwrite
    $ gdal vector info in_epsg_32632.gdalg.json

### Example 3: None

Union 2 source shapefiles (with similar structure), reproject them to EPSG:32632, keep only cities larger than 1 million inhabitants and write to a GeoPackage

    $ gdal vector pipeline --progress ! concat --single --dst-crs=EPSG:32632 france.shp belgium.shp ! filter --where "pop > 1e6" ! write out.gpkg --overwrite