ST_Dimension — Returns the topological dimension of a geometry.
integer ST_Dimension(geometry g
Return the topological dimension of this Geometry object, which must
be less than or equal to the coordinate dimension. OGC SPEC
s18.104.22.168 - returns 0 for
POINT, 1 for
LINESTRING, 2 for
the largest dimension of the components of a
If the dimension is unknown (e.g. for an empty
GEOMETRYCOLLECTION) 0 is returned.
This method implements the SQL/MM specification. SQL-MM 3: 5.1.2
Enhanced: 2.0.0 support for Polyhedral surfaces and TINs was introduced. No longer throws an exception if given empty geometry.
Prior to 2.0.0, this function throws an exception if used with empty geometry.
This function supports Polyhedral surfaces.
This function supports Triangles and Triangulated Irregular Network Surfaces (TIN).
SELECT ST_Dimension('GEOMETRYCOLLECTION(LINESTRING(1 1,0 0),POINT(0 0))'); ST_Dimension ----------- 1