This topic describes the ST_IsClosed function. This function returns true if the input geometry object is closed.
Syntax
boolean ST_IsClosed(geometry g);Parameters
| Parameter | Description |
|---|---|
| g | The geometry object that you want to specify. |
Description
- If you specify a polyhedral surfaces, the result of this function indicates whether the object is an open plane or a closed geometry.
- This function supports 3D objects and does not delete z coordinates.
- This function supports polyhedral surfaces.
- This function supports circular strings and curves.
Examples
- Results returned by specifying a nonclosed geometry object:
SELECT ST_IsClosed('LINESTRING(0 0,0 1)'::geometry); st_isclosed ------------- f (1 row) - Results returned by specifying a closed geometry object:
SELECT ST_IsClosed('LINESTRING(0 0,0 1,1 0,0 0)'::geometry); st_isclosed ------------- t (1 row)