H2GIS

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ST_Reverse

Signature

GEOMETRY ST_Reverse(GEOMETRY geom);

Description

Returns geom with its vertex order reversed.

Component order for GEOMETRYCOLLECTIONs depends on the type.

For MULTIPOINTs and MULTILINESTRINGs, each component Geometry is reversed, and the order of these Geometries is also reversed. For GEOMETRYCOLLECTIONs and MULTIPOLYGONs, component Geometries are reversed but their order is not. This is due to the implementation in JTS.

Examples

SELECT ST_Reverse('MULTIPOINT((4 4), (1 1), (1 0), (0 3))');
-- Answer:         MULTIPOINT((0 3), (1 0), (1 1), (4 4))

SELECT ST_Reverse('LINESTRING(1 1, 2 2, 1 3, 3 3, 5 2, 5 1)');
-- Answer:         LINESTRING(5 1, 5 2, 3 3, 1 3, 2 2, 1 1)

SELECT ST_Reverse(
            'MULTILINESTRING((10 260, 150 290, 186 406, 286 286),
                             (120 120, 130 125, 142 129,
                              360 160, 357 170, 380 340),
                             (1 1, 5 5))');
-- Answer:   MULTILINESTRING((5 5, 1 1),
--                           (380 340, 357 170, 360 160,
--                            142 129, 130 125, 120 120),
--                           (286 286, 186 406, 150 290, 10 260))

SELECT ST_Reverse('POLYGON((2 4, 1 3, 2 1, 6 1, 6 3, 4 4, 2 4))');
-- Answer:         POLYGON((2 4, 4 4, 6 3, 6 1, 2 1, 1 3, 2 4))

SELECT ST_Reverse(
            'MULTIPOLYGON(((2 4, 1 3, 2 1, 6 1, 6 3, 4 4, 2 4)),
                          ((1 6, 6 6, 6 5, 1 5, 1 6)),
                          ((0 1, 1 1, 1 0, 0 0, 0 1)))');
-- Answer:   MULTIPOLYGON(((2 4, 4 4, 6 3, 6 1, 2 1, 1 3, 2 4)),
--                        ((1 6, 1 5, 6 5, 6 6, 1 6)),
--                        ((0 1, 0 0, 1 0, 1 1, 0 1)))

SELECT ST_Reverse('GEOMETRYCOLLECTION(
                      POLYGON((1 2, 4 2, 4 6, 1 6, 1 2)),
                      LINESTRING(2 6, 6 2))');
-- Answer:         GEOMETRYCOLLECTION(
--                    POLYGON((1 2, 1 6, 4 6, 4 2, 1 2)),
--                    LINESTRING(6 2, 2 6))
See also