ST_Force2D-ApsaraDB RDS(RDS)-阿里云帮助中心

Strips all dimensions except x and y from a geometry object, returning a 2D geometry.

Syntax

geometry ST_Force2D(geometry geomA);

Parameter	Description
`geomA`	The geometry object to convert to 2D.

The output geometry retains only the x and y coordinates.
Supported geometry types include circular strings, curves, polyhedral surfaces, triangles, triangulated irregular network (TIN) surfaces, and 3D objects.

SELECT ST_AsEWKT(ST_Force2D(ST_GeomFromEWKT('POINT(1 2 3)')));

Output:

 st_asewkt
------------
 POINT(1 2)
(1 row)