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 OGC Simple Features Implementation Specification for SQL 1.1. s2.1.1.1

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

This method supports Circular Strings and Curves.

Changed: 2.0.0 In prior versions of PostGIS ST_GeomFromText('GEOMETRYCOLLECTION(EMPTY)') was allowed. This is now illegal in PostGIS 2.0.0 to better conform with SQL/MM standards

Examples

SELECT ST_IsEmpty('GEOMETRYCOLLECTION EMPTY'::geometry);

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SELECT ST_IsEmpty('POLYGON EMPTY'::geometry);

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

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Figure

SELECT ST_IsEmpty('POLYGON((1 2,3 4,5 6,1 2))'::geometry) = false;

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(1 row)

Figure

SELECT ST_IsEmpty('CIRCULARSTRING EMPTY'::geometry);

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