ST_Intersects
Determines if two GEOMETRY or GEOGRAPHY objects intersect or touch at a single point. If ST_Disjoint returns TRUE, ST_Intersects returns FALSE for the same GEOMETRY or GEOGRAPHY objects.
GEOGRAPHY Polygons with a vertex or border on the International Date Line (IDL) or the North or South pole are not supported.
Behavior Type
Syntax
ST_Intersects( g1, g2 [USING PARAMETERS bbox={true | false}, spheroid={true | false}])
Arguments
g1 |
Spatial object, type GEOMETRY |
g2 |
Spatial object, type GEOMETRY |
Parameters
bbox = {true | false} |
Boolean. Intersects the bounding box of Default: False |
spheroid = {true | false} |
(Optional) BOOLEAN that specifies whether to use a perfect sphere or WGS84. Default: False |
Returns
BOOLEAN
Supported Data Types
Data Type | GEOMETRY | GEOGRAPHY (WGS84) |
Point |
Yes |
Yes |
Multipoint |
Yes |
No |
Linestring |
Yes |
No |
Multilinestring |
Yes |
No |
Polygon |
Yes |
Yes |
Multipolygon |
Yes |
No |
GeometryCollection |
Yes |
No |
Compatible GEOGRAPHY pairs:
Data Type | GEOGRAPHY (WGS84) |
Point-Point | No |
Linestring-Point | No |
Polygon-Point | Yes |
Multipolygon-Point | No |
Examples
The following examples show how to use ST_Intersects.
Two polygons do not intersect or touch:
=> SELECT ST_Intersects (ST_GeomFromText('POLYGON((-1 2,0 3,0 1,-1 2))'), ST_GeomFromText('POLYGON((1 0,1 1,2 2,1 0))')); ST_Intersects -------------- f (1 row)
Two polygons touch at a single point:
=> SELECT ST_Intersects (ST_GeomFromText('POLYGON((-1 2,0 3,0 1,-1 2))'), ST_GeomFromText('POLYGON((1 0,1 1,0 1,1 0))')); ST_Intersects -------------- t (1 row)
Two polygons intersect:
=> SELECT ST_Intersects (ST_GeomFromText('POLYGON((-1 2, 0 3, 0 1, -1 2))'), ST_GeomFromText('POLYGON((0 2, -1 3, -2 0, 0 2))')); ST_Intersects -------------- t (1 row)