title | description | author | ms.author | ms.date | ms.service | ms.subservice | ms.topic | helpviewer_keywords | dev_langs | ||
---|---|---|---|---|---|---|---|---|---|---|---|
MakeValid (geography Data Type) |
MakeValid (geography Data Type) |
MladjoA |
mlandzic |
03/14/2017 |
sql |
t-sql |
reference |
|
|
[!INCLUDE SQL Server Azure SQL Database Azure SQL Managed Instance]
Converts a geography instance that is not valid into a valid geography instance with a valid Open Geospatial Consortium (OGC) type.
If an input object returns False for STIsValid(), MakeValid()
converts the instance that is not valid to a valid instance.
This geography data type method supports FullGlobe instances or spatial instances that are larger than a hemisphere.
.MakeValid ()
[!INCLUDEsql-server-tsql-previous-offline-documentation]
[!INCLUDEssNoVersion] return type: geography
CLR return type: SqlGeography
This method may change the type of the geography instance. Additionally, the points of a geography instance may shift slightly. Results from some methods such as NumPoint() may change.
In cases where the invalid spatial instance intersects the equator and has an EnvelopeAngle() = 180, a FullGlobe instance will be returned. The MakeValid()
geography data type method will make the best attempt at returning valid instances but the results are not guaranteed to be accurate or precise.
Note
Objects that are not valid can be stored in the database. The methods that can be executed on invalid instances (those instances for which STIsValid() return False) are methods that check validity or allow for export: STIsValid(), MakeValid(), STAsText(), STAsBinary(), ToString(), AsTextZM(), and AsGml().
This method is not precise.
The first example creates an invalid LineString
instance that overlaps itself and uses STIsValid()
to confirm that it is an invalid instance. STIsValid()
returns the value of 0 for an invalid instance.
DECLARE @g geography;
SET @g = geography::STGeomFromText('LINESTRING(0 2, 1 1, 1 0, 1 1, 2 2)', 4326);
SELECT @g.STIsValid();
The second example uses MakeValid()
to make the instance valid and to test that the instance is indeed valid. STIsValid()
returns the value of 1 for a valid instance.
SET @g = @g.MakeValid();
SELECT @g.STIsValid();
The third example verifies how the instance has been changed to make it a valid instance.
SELECT @g.ToString();
In this example, when the LineString
instance is selected, the values are returned as a valid MultiLineString
instance.
MULTILINESTRING ((0 2, 1 1, 2 2), (1 1, 1 0))
STIsValid (geometry Data Type)
Extended Methods on Geography Instances