H2GIS

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ST_RemoveHoles

Signature

GEOMETRY ST_RemoveHoles(GEOMETRY geom);

Description

Removes all holes in geom. Returns geom untouched if it contains no holes. Returns NULL if geom is not a POLYGON or MULTIPOLYGON.

Examples

SELECT ST_RemoveHoles(
            'POLYGON((1 5, 0 4, 0 1, 1 0, 4 0, 4 2, 5 4, 5 4, 1 5),
                     (1 3, 1 4, 2 4, 2 3, 1 3),
                     (2 2, 1 1, 2 1, 2 2))');
-- Answer:   POLYGON((1 5, 0 4, 0 1, 1 0, 4 0, 4 2, 5 4, 5 4, 1 5))

Non-examples
-- Here are no holes to remove:
SELECT ST_RemoveHoles(
          'POLYGON((1 5, 0 4, 0 1, 1 0, 4 0, 4 2, 5 4, 5 4, 1 5))');
-- Answer: POLYGON((1 5, 0 4, 0 1, 1 0, 4 0, 4 2, 5 4, 5 4, 1 5))

-- Returns NULL for POINTS:
SELECT ST_RemoveHoles('POINT(1 5)');
-- Answer: NULL
See also