ST_IsEmpty
Determines if a spatial object represents the empty set.
Determines if a spatial object represents the empty set. An empty object has no dimension.
Behavior type
ImmutableSyntax
ST_IsEmpty( g )
Arguments
g
- Spatial object, type GEOMETRY or GEOGRAPHY
Returns
BOOLEAN
Supported data types
Data Type | GEOMETRY | GEOGRAPHY (Perfect Sphere) | GEOGRAPHY (WGS84) |
---|---|---|---|
Point | Yes | Yes | Yes |
Multipoint | Yes | Yes | Yes |
Linestring | Yes | Yes | Yes |
Multilinestring | Yes | Yes | Yes |
Polygon | Yes | Yes | Yes |
Multipolygon | Yes | Yes | Yes |
GeometryCollection | Yes | No | No |
Examples
The following example shows how to use ST_IsEmpty.
An empty polygon:
=> SELECT ST_IsEmpty(ST_GeomFromText('GeometryCollection EMPTY'));
ST_IsEmpty
------------
t
(1 row)