stnumcurves-geography-data-type.md

title	STNumCurves (geography Data Type)
description	STNumCurves (geography Data Type)
author	MladjoA
ms.author	mlandzic
ms.date	03/14/2017
ms.service	sql
ms.subservice	t-sql
ms.topic	reference
ms.custom	ignite-2024
f1_keywords	STNumCurves STNumCurves_TSQL
helpviewer_keywords	STNumCurves method (geography)
dev_langs	TSQL

STNumCurves (geography Data Type)

[!INCLUDE SQL Server Azure SQL Database Azure SQL Managed Instance FabricSQLDB]

Returns the number of curves in a one-dimensional geography instance.

Syntax

  
.STNumCurves()  

Return Types

[!INCLUDEssNoVersion] return type: geography

CLR return type: SqlGeography

Remarks

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.

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 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 CompoundCurve instance.

 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();

See Also

Spatial Data Types Overview
OGC Methods on Geography Instances