ST_Crosses

Signature

BOOLEAN ST_Crosses(GEOMETRY geomA, GEOMETRY geomB);

Description

Returns TRUE if geomA crosses geomB.

Crosses means that:

The intersection between geomA and geomB gives a new Geometry whose dimension is less than the maximum dimension of the input Geometries.
geomA and geomB have some, but not all interior points in common.
The intersection set is interior to both geomA and geomB.

Note

Implements the OpenGIS Simple Features Implementation Specification for SQL version 1.2.1

Warning

This predicate does not yet support spatial indices, but it will in a future release. Use it in conjunction with && operator. See here for more details.

Note

In the OpenGIS Simple Features Specification this predicate is only defined for (POINT, LINESTRING), (POINT, POLYGON), (LINESTRING, LINESTRING), and (LINESTRING, POLYGON) situations.

JTS and Geos extend this definition to (POLYGON, LINESTRING), (POLYGON, POINT) and (LINESTRING, POINT) situations.

Examples

Cases where `ST_Crosses` is true

SELECT ST_Crosses(geomA, geomB) FROM input_table;
-- Answer:    TRUE

geomA MULTIPOINT	geomB LINESTRING
MULTIPOINT((1 3), (4 1), (4 3))	LINESTRING(1 1, 5 2, 2 5)

geomA MULTIPOINT	geomB POLYGON
MULTIPOINT((1 3), (4 1), (4 3))	POLYGON((2 2, 5 2, 5 5, 2 5, 2 2))

geomA LINESTRING	geomB LINESTRING
LINESTRING(1 3, 5 3)	LINESTRING(1 1, 5 2, 2 5)

geomA LINESTRING	geomB POLYGON
LINESTRING(1 3, 5 3)	POLYGON((2 2, 5 2, 5 5, 2 5, 2 2))

geomA POLYGON	geomB LINESTRING
POLYGON((1 1, 4 1, 4 4, 1 4, 1 1))	LINESTRING(1 5, 5 1)

geomA POLYGON	geomB MULTIPOINT
POLYGON((1 1, 4 1, 4 4, 1 4, 1 1))	MULTIPOINT((2 3), (4 5), (5 1))

geomA LINESTRING	geomB MULTIPOINT
LINESTRING(2 1, 1 3, 3 4)	MULTIPOINT((1 3), (4 1), (4 3))

Cases where `ST_Crosses` is false

SELECT ST_Crosses(geomA, geomB) FROM input_table;
-- Answer:    FALSE

geomA POLYGON	geomB POLYGON
POLYGON((1 1, 4 1, 4 4, 1 4, 1 1))	POLYGON((2 2, 5 2, 5 5, 2 5, 2 2))

geomA POLYGON	geomB POLYGON
LINESTRING(1 1, 5 2, 2 5)	LINESTRING(3 4, 5 2)