other_geometry

Is another geometry instance to form a union with the instance on which STUnion() is being invoked.

SQL Server return type: geometry

CLR return type: SqlGeometry

This method always returns null if the spatial reference IDs (SRIDs) of the geometry instances do not match.

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();

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