STSymDifference (geography Data Type)
Returns an object representing all points that are either in one geography instance or another geography instance, but not those points that lie in both instances.
Syntax
.STSymDifference ( other_geography )
Arguments
- other_geography
Is another geography instance in addition to the instance on which STSymDistance() is being invoked.
Return Types
SQL Server return type: geography
CLR return type: SqlGeography
Remarks
This method always returns null if the spatial reference IDs (SRIDs) of the geography instances do not match.
Examples
The following example uses STSymDifference() to compute the symmetric difference of two Polygon instances.
DECLARE @g geography;
DECLARE @h 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))', 4326);
SET @h = geography::STGeomFromText('POLYGON((-122.351 47.656, -122.341 47.656, -122.341 47.661, -122.351 47.661, -122.351 47.656))', 4326);
SELECT @g.STSymDifference(@h).ToString();