ST_IsValid() method

Determines whether the geometry is a valid spatial object.

Syntax

geometry-expression.ST_IsValid()

BIT Returns 1 if the geometry value is valid, otherwise 0.

Example 1 – The following returns the result 0 because the polygon contains a bow tie (the ring has a self-intersection).
```
SELECT ST_Geometry::ST_GeomFromText( 'Polygon(( 0 0, 4 0, 4 5, 0 -1, 0 0 ))' )
.ST_IsValid()
```
The following returns the result 0 because the polygons within the geometry self-intersect at a surface. Note that self-intersections of a geometry collection at finite number of points is considered valid.
```
SELECT ST_Geometry::ST_GeomFromText(
'MultiPolygon((( 0 0, 2 0, 1 2, 0 0 )),((0 2, 1 0, 2 2, 0 2)))' )
.ST_IsValid()
```

SQL/MM (ISO/IEC 13249-3: 2006) 5.1.9