Returns the shortest distance between a point in a geography instance and a point in another geography instance.
.STDistance ( other_geography )
Is another geography instance from which to measure the distance between the instance on which STDistance() is invoked. If other_geography is an empty set, STDistance() returns null.
SQL Server return type: float
CLR return type: SqlDouble
STDistance() always returns null if the spatial reference IDs (SRIDs) of the geography instances do not match.
If STDistance() is used to determine distance between antipodal points, or consecutive points on opposite sides of the globe, as in the distance between POINT (0 0) and POINT (180 0), this method will return null.
POINT (0 0)
POINT (180 0)
DECLARE @g geography; DECLARE @h geography; SET @g = geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326); SET @h = geography::STGeomFromText('POINT(-122.34900 47.65100)', 4326); SELECT @g.STDistance(@h);