Name
ST_Length — Returns the 2-dimensional length of a Geometry.
Synopsis
double ST_Length(bytea
Geometry);
Description
Returns the 2d length of a Geometry. Linear geometries return their length. Areal geometries return their perimeter.
Spatial Standards OGC defines the function for LineStrings and MultiLineStrings. Jaspa adds support to areal Geometries.
![[Note]](images/note.png) | |
This function supports GeometryCollections. |
Coordinate Dimensions
| 2D | 3D | M |
|---|---|---|
 | - | - |
Spatial Standards Support
| OGC SFS for SQL. 1.1 (1999) | OGC SFS for SQL. 1.1.0 (2005) | OGC SFS for SQL. 1.2.0 (2006) | SQL-MM Part 3 |
|---|---|---|---|
| 2.1.5.1 , 2.1.7.1 | 7.2.12.1 , 7.2.17.1 | 7.2.10.2 , 7.2.17.2 | 7.1.2 , 9.3.4 Linear 8.1.3 , 9.5.4 Areal |
Examples
SELECT ST_Length(ST_GeomFromText('LINESTRING (0 0, 10 10, 10 5, 15 10)'));
--Result
26.213203435596427
SELECT ST_Length2D(ST_GeomFromText('POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))'));
--Result
40.0
SELECT ST_Length(ST_GeomFromText('GEOMETRYCOLLECTION (POINT (40 30),LINESTRING (0 0, 10 10, 10 5, 15 10),POLYGON((0 0, 0 10, 10 10, 10 0, 0 0)))'));
--Result
66.21320343559643