CONTAINS_SEQUENCE()

All functions > ARRAY > CONTAINS_SEQUENCE()

Returns TRUE if the array contains the specified sequence as a contiguous subsequence.

Signatures

Returns: TRUE if sequence appears contiguously in array, FALSE otherwise

CONTAINS_SEQUENCE(array: ARRAY<T>, sequence: ARRAY<T>) → BOOLEAN

Notes

• Checks for contiguous subsequence match
• Elements must appear in order without gaps
• Returns FALSE if sequence is not found
• Every array contains the empty sequence, so an empty sequence is TRUE
• A NULL element matches only a NULL element, so a gap is not a match
• Uses element equality comparison

See also

• Array functions

Examples

RETURN
    -- Contiguous numeric subsequence
    f1 := CONTAINS_SEQUENCE(ARRAY(1, 2, 3, 4), ARRAY(2, 3)),
    -- Contiguous string subsequence
    f2 := CONTAINS_SEQUENCE(ARRAY('a', 'b', 'c'), ARRAY('b', 'c')),
    -- Wrong order is not a match
    f3 := CONTAINS_SEQUENCE(ARRAY(1, 2, 3), ARRAY(3, 2)),
    -- Empty sequence argument
    f4 := CONTAINS_SEQUENCE(ARRAY(1, 2, 3), ARRAY()::ARRAY<BIGINT>)
;