STWithin (geometry Data Type)
SQL Server 2012
Returns 1 if a geometry instance is completely within another geometry instance; otherwise, returns 0.
The following example uses STWithin() to test two geometry instances to see if the first instance is completely within the second instance.
DECLARE @g geometry;
DECLARE @h geometry;
SET @g = geometry::STGeomFromText('POLYGON((0 0, 2 0, 2 2, 0 2, 0 0))', 0);
SET @h = geometry::STGeomFromText('POLYGON((1 1, 3 1, 3 3, 1 3, 1 1))', 0);
SELECT @g.STWithin(@h);
