ST_Perimeter

Signature

DOUBLE ST_Perimeter(GEOMETRY poly);

Description

Returns the perimeter of a polygon or a multipolygon.

Note that (multi)polygons within geometrycollection are accepted.

Perimeter is measured in the units of the spatial reference system.

Note

Implements the OpenGIS Simple Features Implementation Specification for SQL version 1.2.1

Examples

SELECT ST_Perimeter('POLYGON((1 2, 4 2, 4 6, 1 6, 1 2))');
-- Answer: 14.0

SELECT ST_Perimeter('MULTIPOLYGON(((0 2, 3 2, 3 6, 0 6, 0 2)),
                                  ((5 0, 7 0, 7 1, 5 1, 5 0)))');
-- Answer: 20.0

SELECT ST_Perimeter('GEOMETRYCOLLECTION(
                    MULTIPOINT((4 4), (1 1), (1 0), (0 3)),
                    LINESTRING(2 1, 1 3, 5 2),
                    POLYGON((1 2, 4 2, 4 6, 1 6, 1 2)))');
-- Answer: 14.0

SELECT ST_Perimeter('LINESTRING(2 1, 1 3, 5 2)');
-- Answer: 0

See also