Checks whether a geometry object is in a valid format.
Syntax
boolean ST_IsValid(geometry g);
boolean ST_IsValid(geometry g, integer flags);Parameters
| Parameter | Type | Description |
|---|---|---|
g | geometry | The geometry object to check. |
flags | integer | A bitfield that controls validity rules. Set to 1 to treat a self-intersection ring forming a hole as valid. This is the Environmental Systems Research Institute (ESRI) validity flag. |
Description
Returns true if the geometry object is valid, or false if it is not. When the geometry is invalid, the function also outputs a notice that describes the reason for invalidity, such as the location of a self-intersection.
Examples
SELECT ST_IsValid('POLYGON((0 0,0 1,1 0,1 1,0 0))'::geometry);
NOTICE: Self-intersection at or near point 0.5 0.5
st_isvalid
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