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ST_Equals

Tests whether two geometries are spatially equal (represent the same geometry).

Syntax​

ST_Equals(geometry_a, geometry_b)

Parameters​

ParameterTypeDescription
geometry_aGeometryFirst geometry
geometry_bGeometrySecond geometry

Returns​

TypeDescription
BooleanTrue if geometries are spatially equal, false otherwise

Examples​

Same Polygon, Different Order​

SELECT ST_Equals(
    ST_GeomFromText('POLYGON((0 0, 4 0, 4 4, 0 4, 0 0))'),
    ST_GeomFromText('POLYGON((0 4, 0 0, 4 0, 4 4, 0 4))')
);
-- Returns: true (same polygon, different vertex order)

Reversed LineString​

SELECT ST_Equals(
    ST_GeomFromText('LINESTRING(0 0, 1 1, 2 0)'),
    ST_GeomFromText('LINESTRING(2 0, 1 1, 0 0)')
);
-- Returns: true (same line, reversed direction)

Find Duplicate Geometries​

SELECT a.id as id_a, b.id as id_b
FROM features a, features b
WHERE a.id < b.id
  AND ST_Equals(a.geom, b.geom);

Notes​

  • Spatial equality ignores vertex order and direction
  • Different from binary equality (bytes must match)
  • Two geometries are equal if they cover the same space
  • Useful for deduplication and data validation

See Also​