ST_StartPoint-ApsaraDB RDS(RDS)-阿里云帮助中心

Returns the start point of a LineString or circular string geometry. Returns NULL for any other geometry type.

Syntax

geometry ST_StartPoint(geometry geomA)

Parameter	Description
`geomA`	The geometry object.

Preserves z coordinates — 3D geometries are supported without coordinate loss.
Supports circular strings and curves in addition to standard LineString geometries.

Get the start point of a LineString:

SELECT ST_AsText(ST_StartPoint('LINESTRING(0 0,2 2)'::geometry));

Output:

 st_astext
------------
 POINT(0 0)
(1 row)