ST_Holes Signatures GEOMETRYCOLLECTION ST_Holes(GEOMETRY geom) GEOMETRYCOLLECTION ST_Holes(GEOMETRYCOLLECTION geom) Description Returns geom’s holes as a GEOMETRYCOLLECTION. Returns GEOMETRYCOLLECTION EMPTY for Geometries of dimension less than 2. Examples SELECT ST_Holes('POLYGON((0 0, 10 0, 10 5, 0 5, 0 0))'); -- Answer: GEOMETRYCOLLECTION EMPTY SELECT ST_Holes('POLYGON((0 0, 10 0, 10 5, 0 5, 0 0), (1 1, 2 1, 2 4, 1 4, 1 1))'); -- Answer: GEOMETRYCOLLECTION(POLYGON((1 1, 2 1, 2 4, 1 4, 1 1))) SELECT ST_Holes( 'GEOMETRYCOLLECTION( POLYGON((0 0, 10 0, 10 5, 0 5, 0 0), (1 1, 2 1, 2 4, 1 4, 1 1)), POLYGON((11 6, 14 6, 14 9, 11 9, 11 6), (12 7, 14 7, 14 8, 12 8, 12 7)))'); -- Answer: GEOMETRYCOLLECTION( -- POLYGON((1 1, 2 1, 2 4, 1 4, 1 1)), -- POLYGON((12 7, 14 7, 14 8, 12 8, 12 7))) SELECT ST_Holes('LINESTRING(5 5, 1 2, 3 4, 9 3)'); -- Answer: GEOMETRYCOLLECTION EMPTY See also Source code Back Next