STIntersection (geometry Data Type)
SQL Server 2008
Returns an object representing the points where a geometry instance intersects another geometry instance.
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();
