m-geography-data-type.md

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

M (geography Data Type)

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The M (measure) value of the geography instance. The semantics of the measure value are user-defined but generally describe the distance along a linestring. For example, the measure value could be used to keep track of mileposts along a road.

Syntax

  
.M  

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Return Types

[!INCLUDEssNoVersion] type: float

CLR type: SqlDouble

Remarks

The value of this property is null if the geography instance is not a Point, as well as for any Point instance for which it is not set.

This property is read-only.

M values are not used in any calculations made by the library and will not be carried through any library calculations.

Examples

The following example creates a Point instance with Z (elevation) and M (measure) values and uses M to fetch the M value of the instance.

DECLARE @g geography;  
SET @g = geography::STGeomFromText('POINT(-122.34900 47.65100 10.3 12)', 4326);  
SELECT @g.M;  

See Also

Extended Methods on Geography Instances
Z (geography Data Type)