ST_MakeValid

Introduction: Given an invalid geometry, create a valid representation of the geometry.

Collapsed geometries are either converted to empty (keepCollapsed=false) or a valid geometry of lower dimension (keepCollapsed=true). Default is keepCollapsed=false.

Vertex order and ring orientation

ST_MakeValid may reorder coordinates or reverse polygon ring orientation, including for already-valid inputs. To enforce a specific orientation after repair, use ST_ForcePolygonCCW or ST_ForcePolygonCW, for example ST_ForcePolygonCCW(ST_MakeValid(geom)). These functions enforce ring orientation; they are not guaranteed to restore the original vertex order or starting vertex.

Format:

ST_MakeValid (A: Geometry)

ST_MakeValid (A: Geometry, keepCollapsed: Boolean)

Return type: Geometry

Since: v1.5.0

Example:

WITH linestring AS (
    SELECT ST_GeomFromWKT('LINESTRING(1 1, 1 1)') AS geom
) SELECT ST_MakeValid(geom), ST_MakeValid(geom, true) FROM linestring

Result:

+------------------+------------------------+
|st_makevalid(geom)|st_makevalid(geom, true)|
+------------------+------------------------+
|  LINESTRING EMPTY|             POINT (1 1)|
+------------------+------------------------+