STNumCurves (geometry Data Type)


Updated: June 10, 2016

THIS TOPIC APPLIES TO:yesSQL Server (starting with 2008)yesAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

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.

Applies to: SQL Server (SQL Server 2008 through current version), Azure SQL Database.

SQL Server return type: geometry

CLR return type: SqlGeometry

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.

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();

Spatial Data Types Overview
OGC Methods on Geometry Instances

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