<=>
is
operator insteadThe equals comparison (=
) returns unknown if one of the compared values is the null
value. Is not distinct from
is similar to =
but never returns unknown. Instead it returns false if only one argument is null
or true if both arguments are null
.
SELECT …
FROM …
WHERE c1 IS NOT DISTINCT FROM c2
Negation: IS DISTINCT FROM
(null-safe not equals comparison)
Tutorials:
Is not distinct from
is defined in ISO/IEC 9075-2:2023 as the optional feature T152, “DISTINCT predicate with negation”.
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