STExteriorRing (geometry Data Type)

**APPLIES TO:** SQL Server (starting with 2008) Azure SQL Database Azure SQL Data Warehouse Parallel Data Warehouse

Returns the exterior ring of a geometry instance that is a polygon.

Syntax

  
.STExteriorRing ( )  

Return Types

SQL Server return type: geometry

CLR return type: SqlGeometry

Open Geospatial Consortium (OGC) type: LineString

Remarks

This method returns null if the geometry instance is not a polygon.

Examples

The following example creates a Polygon instance and uses STExteriorRing() to return the exterior ring of the polygon as a LineString.

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

See Also

OGC Methods on Geometry Instances