STUnion (geometry Data Type)
Returns an object representing the union of a geometry instance with another geometry instance.
Syntax
.STUnion ( other_geometry )
Arguments
- other_geometry
Is another geometry instance to form a union with the instance on which STUnion() is being invoked.
Return Types
SQL Server return type: geometry
CLR return type: SqlGeometry
Remarks
This method always returns null if the spatial reference IDs (SRIDs) of the geometry instances do not match.
Examples
The following example uses STUnion() to compute the union of two Polygon instances.
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.STUnion(@h).ToString();