Name
ST_IsSimple — Tests if a Geometry has no anomalous geometric points, such as self intersection or self tangency.
Synopsis
boolean ST_IsSimple(bytea
Geometry);
Description
Tests if a Geometry has no anomalous geometric points, such as self intersection or self tangency. If the Geometry is Simple, then returns TRUE. If the Geometry is an empty set, then returns null. Otherwise return False.
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 |
|---|---|---|---|
| 2.1.1.1 | 7.2.10.1 | 7.2.8.2 | 5.1.8 |
Examples
SELECT ST_IsSimple(ST_GeomFromText('MULTIPOINT(0 0 5, 2 2 8)'));
--Result
TRUE
SELECT ST_IsSimple(ST_GeomFromText('MULTIPOINT(0 0 5, 2 2 8, 0 0 8)'));
--Result
FALSE
SELECT IsSimple(ST_GeomFromText('LINESTRING (0 0, 10 10, 20 10, 10 10)'));
--Result
FALSE
SELECT ST_IsSimple(ST_GeomFromText('POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0), (2 2, 2 4, 4 4, 4 2, 2 2))'));
--Result
TRUE
SELECT ST_IsSimple(ST_GeomFromText('POINT EMPTY'));
--Result
null