stintersection-geometry-data-type.md

title	description	author	ms.author	ms.date	ms.service	ms.subservice	ms.topic	f1_keywords	helpviewer_keywords	dev_langs	monikerRange
STIntersection (geometry Data Type)	STIntersection (geometry Data Type)	MladjoA	mlandzic	08/03/2017	sql	t-sql	reference	STIntersection_TSQL STIntersection (geometry Data Type)	STIntersection (geometry Data Type)	TSQL	=azuresqldb-current||>=sql-server-2016||>=sql-server-linux-2017||=azuresqldb-mi-current||=fabric

STIntersection (geometry Data Type)

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Returns an object that represents the points where a geometry instance intersects another geometry instance.

Syntax

  
.STIntersection ( other_geometry )  

[!INCLUDEsql-server-tsql-previous-offline-documentation]

Arguments

other_geometry
Is another geometry instance to compare with the instance on which STIntersection() is being invoked, to determine where they intersect.

Return Types

[!INCLUDEssNoVersion] return type: geometry

CLR return type: SqlGeometry

Remarks

STIntersection() always returns null if the spatial reference IDs (SRIDs) of the geometry instances do not match. The result may contain circular arc segments only if the input instances contain them.

Examples

A. Using STIntersection() on Polygon instances

The following example uses STIntersection() to compute the intersection of two polygons.

DECLARE @g geometry;  
DECLARE @h geometry;  
SET @g = geometry::STGeomFromText('POLYGON((0 0, 0 2, 2 2, 2 0, 0 0))', 0);  
SET @h = geometry::STGeomFromText('POLYGON((1 1, 3 1, 3 3, 1 3, 1 1))', 0);  
SELECT @g.STIntersection(@h).ToString();  

B. Using STIntersection() with CurvePolygon instance

The following example returns an instance that contains a circular arc segment.

 DECLARE @g geometry = 'CURVEPOLYGON (CIRCULARSTRING (0 -4, 4 0, 0 4, -4 0, 0 -4))';  
 DECLARE @h geometry = 'POLYGON ((1 -1, 5 -1, 5 3, 1 3, 1 -1))';  
 SELECT @h.STIntersection(@g).ToString();

See Also

OGC Methods on Geometry Instances