STIsRing (geometry Data Type)

Returns 1 if a geometry instance fulfills the following requirements:

  • It is a LineString instance.

  • It is closed.

  • It is simple.

  • Returns 0 if the LineString instance does not meet the requirements.

For a geometry instance to be closed and simple, both STIsClosed() and STIsSimple() must return 1 when invoked on the instance. To determine the instance type of a geometry, use STGeometryType().


.STIsRing ( )

Return Types

SQL Server return type: bit

CLR return type: SqlBoolean


This method returns null if the instance is not a LineString.


The following example creates a LineString instance and uses STIsRing() to test whether the instance is a ring.

DECLARE @g geometry;
SET @g = geometry::STGeomFromText('LINESTRING(0 0, 2 2, 1 0, 0 0)', 0);
SELECT @g.STIsRing();