STNumCurves (geometry Data Type)
Applies to:
SQL Server
Azure SQL Database
Azure SQL Managed Instance
This method returns the number of curves in a geometry instance when the instance is a one-dimensional spatial data type. One-dimensional spatial data types include LineString, CircularString, and CompoundCurve. STNumCurves
() works only on simple types; it does not work with geometry collections like MultiLineString.
Syntax
.STNumCurves()
Return Types
SQL Server return type: geometry
CLR return type: SqlGeometry
Remarks
An empty one-dimensional geometry instance returns 0. NULL is returned when the geometry instance is not a one-dimensional instance or is an uninitialized instance.
Examples
A. Using STNumCurves() on a CircularString instance
The following example shows how to get the number of curves in a CircularString
instance:
DECLARE @g geometry;
SET @g = geometry::Parse('CIRCULARSTRING(10 0, 0 10, -10 0, 0 -10, 10 0)');
SELECT @g.STNumCurves();
B. Using STNumCurves() on a CompoundCurve instance
The following example uses STNumCurves()
to return the number of curves in a CompoundCurve
instance.
DECLARE @g geometry;
SET @g = geometry::Parse('COMPOUNDCURVE(CIRCULARSTRING(10 0, 0 10, -10 0, 0 -10, 10 0))');
SELECT @g.STNumCurves();
See Also
Spatial Data Types Overview
OGC Methods on Geometry Instances