| title | description | author | ms.author | ms.date | ms.service | ms.subservice | ms.topic | f1_keywords | helpviewer_keywords | dev_langs | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
STPointN (geography Data Type) |
STPointN (geography Data Type) |
MladjoA |
mlandzic |
03/14/2017 |
sql |
t-sql |
reference |
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|
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[!INCLUDE SQL Server Azure SQL Database Azure SQL Managed Instance]
Returns the specified point in a geography instance.
.STPointN ( expression )
[!INCLUDEsql-server-tsql-previous-offline-documentation]
expression
Is an int expression between 1 and the number of points in the geography instance.
[!INCLUDEssNoVersion] return type: geography
CLR return type: SqlGeography
Open Geospatial Consortium (OGC) type: Point
If a geography instance is user-created, STPointN() returns the point specified by expression by ordering the points in the order in which they were originally input.
If a geography instance is constructed by the system, STPointN() returns the point specified by expression by ordering all the points in the same order they would be output: first by geography instance, then by ring within the instance (if appropriate), and then by point within the ring. This order is deterministic.
If this method is called with a value less than 1, it throws an ArgumentOutOfRangeException.
If this method is called with a value greater than the number of points in the instance, it returns null.
The following example creates a LineString instance and uses STPointN() to retrieve the second point in the description of the instance.
DECLARE @g geography;
SET @g = geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326);
SELECT @g.STPointN(2).ToString();