Geometry objects can be explicitly and implicitly cast to any character or binary type. In the case of a character type, the geometry will be presented in EWKT format. In the case of a binary type, the geometry will be presented in WKB format. Character and binary types can also be explicitly and implicitly cast as a geometry value. For binary values, the value must represent a valid geometry in WKB format. For character values, the value must represent a valid geometry in either WKT or EWKT format. If casting from WKB or WKT to a geometry value, the default value SRID of 0 is assigned to the object.

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 is supported.

create table T1 (
V1 Integer primary key,
V2 ST_Geometry(SRID=0),
V3 ST_Geometry);

creates a table with one column associated with the default planar reference system and one with an undefined reference system.