UltraLite supports the following functions of ST_GEOMETRY:

• ST_AsBinary function [Spatial]
• ST_AsExtText function [Spatial]
• ST_AsText function [Spatial]
• ST_Distance function [Spatial]
• ST_Equals function [Spatial]
• ST_IntersectsRect function [Spatial]
• ST_Point function [Spatial]
• ST_PointFromExtText function [Spatial]
• ST_PointFromText function [Spatial]
• ST_PointFromWKB function [Spatial]
• ST_SRID function [Spatial]
• ST_X function [Spatial]
• ST_Y function [Spatial]

The ST_GEOMETRY type is the maximal supertype of the geometry type hierarchy. The ST_GEOMETRY type supports methods that can be applied to any spatial value. The ST_GEOMETRY type cannot be instantiated; instead, a subtype should be instantiated. When working with original formats (WKT or WKB), you can use methods such as ST_PointFromText/ST_PointFromWKB to instantiate the appropriate concrete type representing the value in the original format.

The ST_SRID method can be used to retrieve the spatial reference system associated with the value.

Columns of the ST_GEOMETRY type or any of its subtypes cannot be included in a primary key, unique index, or unique constraint.

UltraLite provides a fixed set of three different reference systems that can be attributed to a column during its creation. Individual geometry objects can be associated with any SRID value except the undefined reference system, and can only be stored in a column associated with a matching SRID value or the undefined reference system.

The predefined reference systems are:

No transformations between reference systems are supported.

The following example illustrates how to create a table with one column associated with the default planar reference system and one with an undefined reference system:

CREATE TABLE T1 (
    V1 INTEGER PRIMARY KEY,
    V2 ST_GEOMETRY(SRID=0),
    V3 ST_GEOMETRY
)

The following SQL statement illustrates how to insert data into the T1 table from the previous example:

INSERT INTO T1(V1, V2, V3) 
    VALUES (1, ST_POINTFROMTEXT('POINT(10 20)', 0), ST_POINT(5, 6, 2163))