ST_Validate

Validate and optionally return a geometry. This function checks if a geometry is valid according to OGC rules; it returns the geometry if valid, or NULL if not.

ST_Validate is available from MariaDB 12.0.

Syntax

ST_Validate(g)

Description

The function checks that a given geometry is compliant with the Well-Known Binary (WKB) format and Spatial Reference System Identifier (SRID) syntax, and is geometrically valid.

It returns the geometry if it's valid, or NULL if not.

The function is useful to filter out invalid geometry data.

Examples

A POINT requires both x and y co-ordinates:

SELECT ST_ASTEXT(ST_VALIDATE(ST_GeomFromText('POINT(1 0)')));          
+-------------------------------------------------------+
| ST_ASTEXT(ST_VALIDATE(ST_GeomFromText('POINT(1 0)'))) |
+-------------------------------------------------------+
| POINT(1 0)                                            |
+-------------------------------------------------------+

SELECT ST_ASTEXT(ST_VALIDATE(ST_GeomFromText('POINT(1)')));  
+-----------------------------------------------------+
| ST_ASTEXT(ST_VALIDATE(ST_GeomFromText('POINT(1)'))) |
+-----------------------------------------------------+
| NULL                                                |
+-----------------------------------------------------+

See Also

• Geometry Constructors

• ST_AsText

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