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ST_CONTAINS ​

Returns TRUE if one GEOGRAPHY object contains another. A GEOGRAPHY A contains B if and only if:

  • All points of B lie inside A (either within the interior or on the boundary)
  • The interiors of A and B share at least one point in common

This function has the following properties:

  • Reflexive: Every GEOGRAPHY object contains itself
  • Antisymmetric: If ST_CONTAINS(A, B) = TRUE and ST_CONTAINS(B, A) = TRUE, then A and B are topologically equal
  • Converse of ST_WITHIN: ST_CONTAINS(A, B) = ST_WITHIN(B, A)

See also:

Syntax ​

sql
ST_CONTAINS(<a>, <b>)

Arguments ​

  • <a> and <b>: The GEOGRAPHY objects to check for containment relationship

Returns ​

Returns TRUE if <a> contains <b>, FALSE otherwise.

Example ​

sql
SELECT ST_CONTAINS('POLYGON((0 0, 0 2, 2 2, 2 0, 0 0))'::GEOGRAPHY, 'POINT(1 1)'::GEOGRAPHY);
-- TRUE

SELECT ST_CONTAINS('POLYGON((0 0, 0 2, 2 2, 2 0, 0 0))'::GEOGRAPHY, 'POINT(3 3)'::GEOGRAPHY);
-- FALSE