STNumCurves (geography Data Type)
Returns the number of curves in a one-dimensional geography instance.
To view Transact-SQL syntax for SQL Server 2014 and earlier, see Previous versions documentation.
SQL Server return type: geography
CLR return type: SqlGeography
One-dimensional spatial data types include LineString, CircularString, and CompoundCurve. An empty one-dimensional geography instance returns 0.
STNumCurves() works only on simple types; it does not work with geography collections like MultiLineString. NULL is returned when the geography instance is not a one-dimensional data type.
Null is returned for uninitialized geography instances.
A. Using STNumCurves() on a CircularString instance
The following example shows how to get the number of curves in a
DECLARE @g geography; SET @g = geography::Parse('CIRCULARSTRING(-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653)'); SELECT @g.STNumCurves();
B. Using STNumCurves() on a CompoundCurve instance
The following example uses
STNumCurves() to return the number of curves in a
DECLARE @g geography; SET @g = geography::Parse('COMPOUNDCURVE(CIRCULARSTRING(-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))'); SELECT @g.STNumCurves();