ST_Crosses
ST_Crosses returns true if the 2D projections of the two input geometries cross each other.
Syntax
ST_Crosses(geom1, geom2)
Arguments
- geom1
-
A value of data type
GEOMETRY
or an expression that evaluates to aGEOMETRY
type. - geom2
-
A value of data type
GEOMETRY
or an expression that evaluates to aGEOMETRY
type.
Return type
BOOLEAN
If geom1 or geom2 is null, then an error is returned.
If geom1 or geom2 is a geometry collection, then an error is returned.
If geom1 and geom2 don't have the same value for the spatial reference system identifier (SRID), then an error is returned.
Examples
The following SQL checks if the first polygon crosses the second multipoint. In this example, the multipoint intersects both the interior and exterior of the polygon, which is why ST_Crosses returns true.
SELECT ST_Crosses (ST_GeomFromText('polygon((0 0,10 0,10 10,0 10,0 0))'), ST_GeomFromText('multipoint(5 5,0 0,-1 -1)'));
st_crosses
-------------
true
The following SQL checks if the first polygon crosses the second multipoint. In this example, the multipoint intersects the exterior of the polygon but not its interior, which is why ST_Crosses returns false.
SELECT ST_Crosses (ST_GeomFromText('polygon((0 0,10 0,10 10,0 10,0 0))'), ST_GeomFromText('multipoint(0 0,-1 -1)'));
st_crosses
-------------
false