STNumCurves (geometry Data Type)

Article
11/19/2024

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance SQL database in Microsoft Fabric

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();

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