ST_StartPoint — Returns the first point of a LINESTRING
geometry as a POINT
.
geometry ST_StartPoint(
geometry geomA)
;
Returns the first point of a LINESTRING
geometry
as a POINT
or NULL
if the input
parameter is not a LINESTRING
.
This method implements the SQL/MM specification: SQL-MM 3: 7.1.3
This function supports 3d and will not drop the z-index.
SELECT ST_AsText(ST_StartPoint('LINESTRING(0 1, 0 2)'::geometry)); st_astext ------------ POINT(0 1) (1 row) SELECT ST_StartPoint('POINT(0 1)'::geometry) IS NULL AS is_null; is_null ---------- t (1 row) --3d line SELECT ST_AsEWKT(ST_StartPoint('LINESTRING(0 1 1, 0 2 2)'::geometry)); st_asewkt ------------ POINT(0 1 1) (1 row)