STDimension (geography Data Type)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Returns the maximum dimension of a geography instance.
Syntax
.STDimension ( )
Return Types
SQL Server return type: int
CLR return type: SqlInt32
Remarks
STDimension() returns -1 if the geography instance is empty.
Examples
The following example uses STDimension() to create a table variable to hold geography instances, and inserts a Point, a LineString, and a Polygon.
DECLARE @temp table ([name] varchar(10), [geom] geography);
INSERT INTO @temp values ('Point', geography::STGeomFromText('POINT(-122.34900 47.65100)', 4326));
INSERT INTO @temp values ('LineString', geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326));
INSERT INTO @temp values ('Polygon', geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326));
SELECT [name], [geom].STDimension() as [dim]
FROM @temp;
The example then returns the dimensions of each geographyinstance.
| name | dim |
|---|---|
| Point | 0 |
| LineString | 1 |
| Polygon | 2 |