# OSGeo::FDO::Expression

## Classes
class | OSGeo::FDO::Expression::BinaryExpression
| The BinaryExpression class derives from Expression and represents string concatenation and the simple arithmetic operations add, subtract, multiply, and divide. More...
class | OSGeo::FDO::Expression::BLOBValue
| The BLOBValue class derives from LOBValue and represents a literal BLOB value. More...
class | OSGeo::FDO::Expression::BooleanValue
| The BooleanValue class derives from DataValue and represents a Boolean value. More...
class | OSGeo::FDO::Expression::ByteValue
| The ByteValue class derives from DataValue and represents a literal byte value. More...
class | OSGeo::FDO::Expression::CLOBValue
| The CLOBValue class derives from LOBValue and represents a literal CLOB value. More...
class | OSGeo::FDO::Expression::ComputedIdentifier
| The ComputedIdentifier class derives from Identifier and represents an expression with alias. The name or alias must be a simple name and should not be scoped or contain the the schema name. The ComputedIdentifier can be used to provide an alias to an expression. More...
class | OSGeo::FDO::Expression::DataValue
| The DataValue class derives from LiteralValue and represents a literal value such as a string or a number. More...
class | OSGeo::FDO::Expression::DataValueCollection
| DataValueCollection is a collection of DataValue objects. More...
class | OSGeo::FDO::Expression::DateTimeValue
| The DateTimeValue class derives from DataValue and represents a date or time. More...
class | OSGeo::FDO::Expression::DecimalValue
| The DecimalValue class derives from DataValue and represents a decimal value. More...
class | OSGeo::FDO::Expression::DoubleValue
| The DoubleValue class derives from DataValue and represents a double-precision floating point number. More...
class | OSGeo::FDO::Expression::Expression
| Expression is an abstract base class that forms the root of an expression tree. The Expression class contains operations for converting between the well defined text representation and the object representation of an expression. More...
class | OSGeo::FDO::Expression::ExpressionCollection
| ExpressionCollection is a collection of Expression objects. More...
class | OSGeo::FDO::Expression::Function
| The Function class derives from Expression and represents a function call. As such it defines the name of the function and the collection of arguments to be passed to it. More...
class | OSGeo::FDO::Expression::GeometryValue
| The GeometryValue class derives from LiteralValue and represents a geometric value. More...
class | OSGeo::FDO::Expression::Identifier
| The Identifier class derives from Expression and represents an identifier, such as a class name or property name. Identifiers can be just a name or they can be scoped to a particular context. For example, consider a Person class that has a DataProperty called "Name" and a ClassProperty called "Address". The Address class has DataProperties "Street", "City", and "Zip Code". When manipulating instances of a Person, the "Name" property can be referred to by the property name "Name". The "City" property is scoped inside the "Address" property, hence must be referred to by the property name "Address.City". More...
interface | OSGeo::FDO::Expression::IExpressionProcessor
| The IExpressionProcessor interface can be used to process the nodes in an Expression tree. It declares an process operation for each concrete class in the Expression hierarchy. Providers or client applications can create classes that realize this interface to do something meaningful with an Expression hierarchy. For example, an RDBMS feature provider implements a processor class to convert an Expression hierarchy to the SQL equivalent syntax. More...
class | OSGeo::FDO::Expression::IExpressionProcessorImp
| The IExpressionProcessor interface can be used to process the nodes in an Expression tree. It declares an process operation for each concrete class in the Expression hierarchy. Providers or client applications can create classes that realize this interface to do something meaningful with an Expression hierarchy. For example, an RDBMS feature provider implements a processor class to convert an Expression hierarchy to the SQL equivalent syntax. More...
class | OSGeo::FDO::Expression::Int16Value
| The Int16Value class derives from DataValue and represents a 16-bit signed integer value. More...
class | OSGeo::FDO::Expression::Int32Value
| The Int32Value class derives from DataValue and represents a 32-bit signed integer value. More...
class | OSGeo::FDO::Expression::Int64Value
| The Int64Value class derives from DataValue and represents a 64-bit signed integer value. More...
class | OSGeo::FDO::Expression::LiteralValue
| LiteralValue is an abstract base class that derives from ValueExpression to form the root for all literal value types. More...
class | OSGeo::FDO::Expression::LiteralValueCollection
| LiteralValueCollection is a collection of LiteralValue objects. More...
class | OSGeo::FDO::Expression::LOBValue
| The LOBValue class derives from DataValue and represents a literal BLOB value. More...
class | OSGeo::FDO::Expression::Parameter
| The Parameter class derives from ValueExpression and represents a substitution parameter in the expression. Parameters are represented by a name: when expressions are evaluated, the caller must supply a value to be bound to each parameter name. More...
class | OSGeo::FDO::Expression::SingleValue
| The SingleValue class derives from DataValue and represents a single precision floating point number. More...
class | OSGeo::FDO::Expression::StringValue
| The StringValue class derives from DataValue and represents a literal string. More...
class | OSGeo::FDO::Expression::UnaryExpression
| The UnaryExpression class derives from Expression and allows negation of arithmetic expressions. More...
class | OSGeo::FDO::Expression::ValueExpression
| ValueExpression is an abstract base class that derives from Expression to form the root for all value expression types. More...
## Enumerations
enum | OSGeo::FDO::Expression::BinaryOperations { OSGeo::FDO::Expression::BinaryOperations_Add = FdoBinaryOperations_Add, OSGeo::FDO::Expression::BinaryOperations_Subtract = FdoBinaryOperations_Subtract, OSGeo::FDO::Expression::BinaryOperations_Multiply = FdoBinaryOperations_Multiply, OSGeo::FDO::Expression::BinaryOperations_Divide = FdoBinaryOperations_Divide }
| The BinaryOperations enumeration lists the binary expression operations available. More...
enum | ExpressionType { ExpressionType_Basic = FdoExpressionType_Basic, ExpressionType_Function = FdoExpressionType_Function, ExpressionType_Parameter = FdoExpressionType_Parameter }
| The ExpressionType enumeration defines the expression types available. This enumeration is used in the capabilities metadata. More...
enum | LiteralValueType { LiteralValueType_Data = FdoLiteralValueType_Data, LiteralValueType_Geometry = FdoLiteralValueType_Geometry }
| The LiteralValueType enumeration defines the literal value types available. More...
enum | UnaryOperations { UnaryOperations_Negate = FdoUnaryOperations_Negate }
| The UnaryOperations enumeration lists the unary expression operations available. More...