STV_LineStringPoint

Retrieves the vertices of a linestring or multilinestring. The values returned are points of either GEOMETRY or GEOGRAPHY type depending on the input object's type. GEOMETRY points inherit the SRID of the input object.

STV_LineStringPoint is an analytic function. For more information, see Analytic functions.

Behavior type

Syntax

STV_LineStringPoint( g )
    OVER( [PARTITION NODES] ) AS

Arguments

g

Linestring or multilinestring, value of type GEOMETRY or GEOGRAPHY

Returns

GEOMETRY or GEOGRAPHY

Supported data types

Examples

The following examples show how to use STV_LineStringPoint.

Returns the vertices of the geometry linestring and their SRID:

=> SELECT ST_AsText(Point), ST_SRID(Point)
     FROM (SELECT STV_LineStringPoint(
           ST_GeomFromText('MULTILINESTRING((1 2, 2 3, 3 1, 4 2),
                  (10 20, 20 30, 30 10, 40 20))', 4269)) OVER () AS Point) AS foo;
    ST_AsText   | ST_SRID
 ---------------+---------
  POINT (1 2)   |    4269
  POINT (2 3)   |    4269
  POINT (3 1)   |    4269
  POINT (4 2)   |    4269
  POINT (10 20) |    4269
  POINT (20 30) |    4269
  POINT (30 10) |    4269
  POINT (40 20) |    4269
 (8 rows)

Returns the vertices of the geography linestring:

=> SELECT ST_AsText(g)
     FROM (SELECT STV_LineStringPoint(
       ST_GeographyFromText('MULTILINESTRING ((42.1 71.0, 41.4 70.0, 41.3 72.9),
           (42.99 71.46, 44.47 73.21)', 4269)) OVER () AS g) AS line_geog_points;
      ST_AsText
---------------------
 POINT (42.1 71.0)
 POINT (41.4 70.0)
 POINT (41.3 72.9)
 POINT (42.99 71.46)
 POINT (44.47 73.21)
(5 rows)

See also