ST_Multi

Signature

GEOMETRY ST_Multi(GEOMETRY geom);

Description

Takes a geometry (geom) and converts it as a geometry collection (MULTI).

If the geometry is already a collection (MULTI), it is returned unchanged.

Examples

With `POINT`, `LINESTRING` and `POLYGON`

SELECT ST_MULTI('POINT(0 0)');

-- Answer: MULTIPOINT ((0 0))

SELECT ST_MULTI('LINESTRING (130 180, 260 170)');

-- Answer: MULTILINESTRING ((130 180, 260 170))

SELECT ST_MULTI('POLYGON((0 0,0 1,1 1,1 0,0 0))');

-- Answer: MULTIPOLYGON (((0 0, 0 1, 1 1, 1 0, 0 0)))

A `MULTI` geometry remains the same

SELECT ST_MULTI('MULTIPOLYGON (((114 186, 180 186, 180 120, 114 120, 114 186)), 
	                          ((220 170, 250 170, 250 120, 220 120, 220 170)))');

-- Answer:       MULTIPOLYGON (((114 186, 180 186, 180 120, 114 120, 114 186)), 
--                            ((220 170, 250 170, 250 120, 220 120, 220 170)))

A `GEOMETRYCOLLECTION` geometry remains the same

SELECT ST_MULTI('GEOMETRYCOLLECTION (LINESTRING (30 80, 225 86), 
	                                 POINT (136 124))');

-- Answer: GEOMETRYCOLLECTION (LINESTRING (30 80, 225 86), POINT (136 124))

See also

Source code