# OSGeo::FDO::Filter Namespace Reference

## Classes
class | BinaryLogicalOperator
| The BinaryLogicalOperator class derives from LogicalOperator and allows two filters to be combined via a logical "and" or a logical "or". More...
class | ComparisonCondition
| The ComparisonCondition class derives SearchCondition and can be used to test the equality of two expressions. More...
class | DistanceCondition
| The DistanceCondition class derives GeometricCondition and can be used to test whether the value of a geometric property is within or beyond a specified distance of the specified geometric value. Some feature providers may only support literal geometric values; if so, the provider's capabilities will indicate this limitation. More...
class | Filter
| Filter is an abstract class which acts as a base class for condition and operator classes that can occur in a filter expression tree. The Filter class contains operations for converting between the text and expression tree representation of a filter. More...
class | GeometricCondition
| GeometricCondition is an abstract class that derives from SearchCondition and can be used to test whether the value of a geometric property meets a particular spatial criteria. GeometricCondition is the base class for DistanceCondition and SpatialCondition. More...
interface | IFilterProcessor
| The IFilterProcessor interface can be used to process the nodes in a filter tree. It declares a process operation for each concrete class in the filter hierarchy. Providers or client applications can create classes that realize this interface to do something meaningful with a filter hierarchy. For example, a RDBMS feature provider can implement a processor class to convert a filter hierarchy to the SQL equivalent syntax. More...
class | IFilterProcessorImp
| The IFilterProcessor interface can be used to process the nodes in a filter tree. It declares a process operation for each concrete class in the filter hierarchy. Providers or client applications can create classes that realize this interface to do something meaningful with a filter hierarchy. For example, a RDBMS feature provider can implement a processor class to convert a filter hierarchy to the SQL equivalent syntax. More...
class | InCondition
| The InCondition class derives from SearchCondition and can be used to test if the value of a specified data property is within a given set of literal values. More...
class | LogicalOperator
| The LogicalOperator is an abstract base class. BinaryLogicalOperator and UnaryLogicalOperator derive from the LogicalOperator class. More...
class | NullCondition
| The NullCondition class derives from SearchCondition and can be used to test if the value of a specified data property is null. More...
class | SearchCondition
| The SearchCondition is an abstract base class. SpatialCondition, ComparisonCondition, LikeCondition, InCondition, and NullCondition derive from the SearchCondition class. More...
class | SpatialCondition
| The SpatialCondition class derives from GeometricCondition and can be used to test whether the value of a geometric property (referenced using the name of the property) and another geometric value satisfy the spatial relationship implied by the operation. Some feature providers may only support literal geometric values; if so, the provider's capabilities will indicate this limitation. More...
class | UnaryLogicalOperator
| The UnaryLogicalOperator class derives from LogicalOperator and allows a logical "Not" to be performed against a filter. More...
class | ValueExpressionCollection
| The ValueExpressionCollection is a collection of ValueExpression objects. More...
## Variables
public __gc __interface | IFilterProcessor