ST_Length

Signature

DOUBLE ST_Length(GEOMETRY linestring);

Description

Returns the length of (multi)Linestring.

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

Warning

Note that (multi)points, (multi)polygons or GeometryCollections return 0.0.

Note

Implements the OpenGIS Simple Features Implementation Specification for SQL version 1.2.1

Examples

SELECT ST_Length('LINESTRING(2 1, 1 3, 5 2)');
-- Answer: 6.35917360311745

SELECT ST_Length('MULTILINESTRING ((1 1, 1 2, 2 2),
                                   (2 1, 3 1, 3 3))');
-- Answer: 5

Cases where `ST_Length` returns `0`

SELECT ST_Length('MULTIPOINT((4 4), (1 1), (1 0), (0 3)))');
-- Answer: 0.0

SELECT ST_Length('POLYGON((1 2, 4 2, 4 6, 1 6, 1 2))');
-- Answer: 0.0

SELECT ST_Length('MULTIPOLYGON(((0 2, 3 2, 3 6, 0 6, 0 2)),
                               ((5 0, 7 0, 7 1, 5 1, 5 0)))');
-- Answer: 0.0

SELECT ST_Length('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: 0.0