STV_PolygonPoint

Retrieves the vertices of a polygon as individual points. 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_PolygonPoint is an analytic function. For more information, see Analytic functions.

Behavior type

Syntax

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

Arguments

g

Polygon, value of type GEOMETRY or GEOGRAPHY

Returns

GEOMETRY or GEOGRAPHY

Supported data types

Examples

The following examples show how to use STV_PolygonPoint.

Returns the vertices of the geometry polygon:

=> SELECT ST_AsText(g) FROM (SELECT STV_PolygonPoint(ST_GeomFromText('POLYGON((1 2, 2 3, 3 1, 1 2))'))
     OVER (PARTITION NODES) AS g) AS poly_points;
  ST_AsText
-------------
 POINT (1 2)
 POINT (2 3)
 POINT (3 1)
 POINT (1 2)
(4 rows)

Returns the vertices of the geography polygon:

=> SELECT ST_AsText(g) FROM (SELECT STV_PolygonPoint(ST_GeographyFromText('
              POLYGON((25.5 28.76, 28.83 29.13, 27.2 30.99, 25.5 28.76))'))
   OVER (PARTITION NODES) AS g) AS poly_points;
      ST_AsText
---------------------
 POINT (25.5 28.76)
 POINT (28.83 29.13)
 POINT (27.2 30.99)
 POINT (25.5 28.76)
(4 rows)

See also