Given two shapes A and B, ST_Intersects(A, B)
returns true
if the shapes share any of the same space -- that is, if any point in the set that comprises A is also a member of the set of points that make up B.
ST_Intersects
works on the following data types:
ST_Intersects
will attempt to use any available spatial index to speed up its operation. Use the prefixed variant _ST_Intersects
if you do not want any spatial indexes to be used.
This function is the inverse of ST_Disjoint
.
Examples
The screenshots in these examples were generated using geojson.io, but they are designed to showcase the shapes, not the map. Representing GEOMETRY
data in GeoJSON can lead to unexpected results if using geometries with SRIDs other than 4326 (as shown below).
True
In this example, ST_Intersects
returns true
because:
- The shapes share some of the same space -- that is, there are Points in the set that comprises Polygon A that are also members of Polygon B.
SELECT st_intersects(st_geomfromtext('SRID=4326;POLYGON((-87.906471 43.038902, -95.992775 36.153980, -75.704722 36.076944, -87.906471 43.038902))'), st_geomfromtext('SRID=4326;POLYGON((-84.191605 39.758949, -75.165222 39.952583, -78.878738 42.880230, -84.191605 39.758949))'));
st_intersects
---------------
true
(1 row)
False
In this example, ST_Intersects
returns false
because:
- The shapes do not share any of the same space -- that is, there are no Points in the set that comprises Polygon A that are also members of Polygon B.
SELECT st_intersects(st_geomfromtext('SRID=4326;POLYGON((-87.906471 43.038902, -95.992775 36.153980, -75.704722 36.076944, -87.906471 43.038902))'), st_geomfromtext('SRID=4326;POLYGON((-79.995888 40.440624,-74.666728 40.358244, -76.5 42.443333, -79.995888 40.440624))'));
st_intersects
---------------
false
(1 row)
See also
- Working with Spatial Data
- Spatial tutorial
- Spatial and GIS Glossary of Terms
- Spatial indexes
- Spatial functions
ST_Covers
ST_CoveredBy
ST_Contains
ST_Within
ST_CoveredBy
ST_Covers
ST_Disjoint
ST_Equals
ST_Overlaps
ST_Touches
ST_ConvexHull
ST_Union
- Migrate from Shapefiles
- Migrate from GeoJSON
- Migrate from GeoPackage
- Migrate from OpenStreetMap
- Introducing Distributed Spatial Data in Free, Open Source CockroachDB (blog post)
- Using GeoServer with CockroachDB