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ST_Intersects

Tests whether two geometries have any point in common (intersect).

Syntax​

ST_Intersects(geometry_a, geometry_b)

Parameters​

ParameterTypeDescription
geometry_aGeometryFirst geometry
geometry_bGeometrySecond geometry

Returns​

TypeDescription
BooleanTrue if geometries intersect, false otherwise

Examples​

Test Point in Polygon​

SELECT ST_Intersects(
    ST_Point(2, 2),
    ST_GeomFromText('POLYGON((0 0, 4 0, 4 4, 0 4, 0 0))')
);
-- Returns: true

Spatial Join​

SELECT a.id, b.name
FROM points a, regions b
WHERE ST_Intersects(a.geom, b.geom);

Find Overlapping Features​

SELECT a.id as id_a, b.id as id_b
FROM parcels a, parcels b
WHERE a.id < b.id
  AND ST_Intersects(a.geom, b.geom);

Notes​

  • Returns true if geometries share any point (interior or boundary)
  • Opposite of ST_Disjoint
  • Most commonly used spatial predicate for spatial joins
  • Uses GEOS for computation

See Also​