Returns an object that represents the convex hull of a geography instance.
.STConvexHull ( )
SQL Server return type: geography
CLR return type: SqlGeography
Returns a FullGlobe
object for geography instance which has an envelope angle larger than 90 degrees.
Returns an empty geography collection for an empty geography instance.
Returns null for an uninitialized geography instance.
The following example uses STConvexHull()
on an uninitialized geography instance.
DECLARE @g geography;
SELECT @g.STConvexHull();
The following example uses STConvexHull()
on an empty Polygon
instance.
DECLARE @g geography = 'POLYGON EMPTY';
SELECT @g.STConvexHull().ToString();
The following example uses STConvexHull()
to find the convex hull of a non-convex Polygon
instance.
DECLARE @g geography;
SET @g = geography::Parse('POLYGON((-120.533 46.566, -118.283 46.1, -122.3 47.45, -120.533 46.566))');
SELECT @g.STConvexHull().ToString();
The following example uses STConvexHull()
on a geography instance with an envelope angle larger than 90 degrees.
DECLARE @g geography = 'POLYGON((20.533 46.566, -18.283 46.1, -22.3 47.45, 20.533 46.566))';
SELECT @g.STConvexHull().ToString();