ST_Intersection method for type ST

ST_Intersection method for type ST_Geometry

Returns the geometry value that represents the point set intersection of two geometries.

Syntax

geometry-expression.ST_Intersection(geo2)

Parameters

Name	Type	Description
geo2	ST_Geometry	The other geometry value that is to be intersected with the geometry-expression.

Returns

ST_Geometry Returns the geometry value that represents the point set intersection of two geometries.
The spatial reference system identifier of the result is the same as the spatial reference system of the geometry-expression.

The ST_Intersection method finds the spatial intersection of two geometries. A point is included in the intersection if it is present in both of the input geometries. If the two geometries don't share any common points, the result is an empty geometry.

Note

If the geometry-expression contains circular strings, then these are interpolated to line strings.

Standards and compatibility

Example

The following example shows the intersection (C) of a square (A) and a circle (B).

SELECT NEW ST_Polygon( 'Polygon( (-1 -0.25, 1 -0.25, 1 2.25, -1 2.25, -1 -0.25) )' ) AS A
    , NEW ST_CurvePolygon( 'CurvePolygon( CircularString( 0 1, 1 2, 2 1, 1 0, 0 1 ) )' )  AS B
    , A.ST_Intersection( B ) AS C

The intersection is shaded in the following picture. It is a single surface that includes all of the points that are in the square and also in the circle.

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