STLength (geometry Data Type)
Returns the total length of the elements in a geometry instance.
.STLength ( )
SQL Server return type: float
CLR return type: SqlDouble
If a geometry instance is closed, its length is calculated as the total length around the instance; the length of any polygon is its perimeter and the length of a point is 0. The length of any geometrycollection type is the sum of the lengths of its contained geometry instances.
The following example creates a LineString instance and uses STLength() to find the length of the instance.
DECLARE @g geometry; SET @g = geometry::STGeomFromText('LINESTRING(0 0, 2 2, 1 0)', 0); SELECT @g.STLength();