Name

ST_Intersects — Returns TRUE if the Geometries/Geography "spatially intersect in 2D" - (share any portion of space) and FALSE if they don't (they are Disjoint). For geography -- tolerance is 0.00001 meters (so any points that close are considered to intersect)

Synopsis

boolean ST_Intersects( geometry geomA , geometry geomB );

boolean ST_Intersects( geography geogA , geography geogB );

Description

Overlaps, Touches, Within all imply spatial intersection. If any of the aforementioned returns true, then the geometries also spatially intersect. Disjoint implies false for spatial intersection.

[Important]

Do not call with a GEOMETRYCOLLECTION as an argument for geometry version. The geography version supports GEOMETRYCOLLECTION since its a thin wrapper around distance implementation.

Performed by the GEOS module (for geometry), geography is native

Availability: 1.5 support for geography was introduced.

[Note]

This function call will automatically include a bounding box comparison that will make use of any indexes that are available on the geometries.

[Note]

For geography, this function has a distance tolerance of about 0.00001 meters and uses the sphere rather than spheroid calculation.

[Note]

NOTE: this is the "allowable" version that returns a boolean, not an integer.

This method implements the OpenGIS Simple Features Implementation Specification for SQL 1.1. s2.1.1.2 //s2.1.13.3 - ST_Intersects(g1, g2 ) --> Not (ST_Disjoint(g1, g2 ))

This method implements the SQL/MM specification. SQL-MM 3: 5.1.27

Geometry Examples

SELECT ST_Intersects('POINT(0 0)'::geometry, 'LINESTRING ( 2 0, 0 2 )'::geometry);
 st_intersects
---------------
 f
(1 row)
SELECT ST_Intersects('POINT(0 0)'::geometry, 'LINESTRING ( 0 0, 0 2 )'::geometry);
 st_intersects
---------------
 t
(1 row)
		

Geography Examples

SELECT ST_Intersects(
		ST_GeographyFromText('SRID=4326;LINESTRING(-43.23456 72.4567,-43.23456 72.4568)'),
		ST_GeographyFromText('SRID=4326;POINT(-43.23456 72.4567772)')
		);

 st_intersects
---------------
t

See Also

ST_3DIntersects, ST_Disjoint