Re: NULL safe equality operator

[Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au>]

> CREATE OR REPLACE FUNCTION null_safe_cmp (ANYELEMENT, ANYELEMENT)
> RETURNS INTEGER IMMUTABLE
> LANGUAGE SQL AS $$
> SELECT CASE
>     WHEN NOT ($1 IS DISTINCT FROM $2) THEN 1
>     ELSE 0
> END;
> $$;

Even cooler:

CREATE OR REPLACE FUNCTION null_safe_cmp(anyelement, anyelement)
RETURNS integer AS '
  SELECT (NOT ($1 IS DISTINCT FROM $2))::integer
' IMMUTABLE LANGUAGE SQL;