Description

Returns true if this Geometry is an empty geometry . If true, then this Geometry represents an empty geometry collection, polygon, point etc.

	SQL-MM defines the result of ST_IsEmpty(NULL) to be 0, while PostGIS returns NULL.

This method implements the OpenGIS Simple Features Implementation Specification for SQL. OGC SPEC s2.1.1.1

This method implements the SQL/MM specification: SQL-MM 3: 5.1.7

This method supports Circular Strings and Curves

Examples

SELECT ST_IsEmpty('GEOMETRYCOLLECTION(EMPTY)');
 st_isempty
------------
 t
(1 row)

 SELECT ST_IsEmpty(ST_GeomFromText('POLYGON EMPTY'));
 st_isempty
------------
 t
(1 row)

SELECT ST_IsEmpty(ST_GeomFromText('POLYGON((1 2, 3 4, 5 6, 1 2))'));

 st_isempty
------------
 f
(1 row)

 SELECT ST_IsEmpty(ST_GeomFromText('POLYGON((1 2, 3 4, 5 6, 1 2))')) = false;
 ?column?
----------
 t
(1 row)

 SELECT ST_IsEmpty(ST_GeomFromText('CIRCULARSTRING EMPTY'));
  st_isempty
------------
 t
(1 row)