RingN (geography Data Type)

THIS TOPIC APPLIES TO:yesSQL Server (starting with 2008)yesAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

Returns the specified ring of the geography instance: 1 ≤ n ≤ NumRings().


.RingN (expression )  


Is an int expression between 1 and the number of rings in a polygon instance.

Return Value

SQL Server return type: geography

CLR return type: SqlGeography


If the value of the ring index n is less than 1, this method throws an ArgumentOutOfRangeException. The ring index value must be greater than or equal to 1 and should be less than or equal to the number returned by NumRings().


This example creates a Polygon instance with two rings and returns the second ring.

DECLARE @g geography;  
SET @g = geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653), (-122.357 47.654, -122.357 47.657, -122.349 47.657, -122.349 47.650, -122.357 47.654))', 4326);  
SELECT @g.RingN(2).ToString();  

See Also

Extended Methods on Geography Instances
NumRings (geography Data Type)