M (geography Data Type)

APPLIES TO: yesSQL Server (starting with 2008) yesAzure SQL Database noAzure SQL Data Warehouse noParallel Data Warehouse

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  

Return Types

SQL Server 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)