sí, hayIS DISTINCT FROM y IS NOT DISTINCT FROM

 postgres=# \pset null **** Null display is "****". postgres=# select null = null; ┌──────────┐ │ ?column? │ ╞══════════╡ │ **** │ └──────────┘ (1 row) postgres=# select null is not distinct from null; ┌──────────┐ │ ?column? │ ╞══════════╡ │ t │ └──────────┘ (1 row) postgres=# select 10 = null; ┌──────────┐ │ ?column? │ ╞══════════╡ │ **** │ └──────────┘ (1 row) postgres=# select 10 is distinct from null; ┌──────────┐ │ ?column? │ ╞══════════╡ │ t │ └──────────┘ (1 row) postgres=# select 10 is not distinct from null; ┌──────────┐ │ ?column? │ ╞══════════╡ │ f │ └──────────┘ (1 row) postgres=# select 10 is not distinct from 20; ┌──────────┐ │ ?column? │ ╞══════════╡ │ f │ └──────────┘ (1 row)

Sí, lo hay , pero se recomienda no usarlo . aquí está la muestra:

 t=# select null = null; ?column? ---------- (1 row) t=# set transform_null_equals = on; SET t=# select null = null; ?column? ---------- t (1 row)

ACTUALIZACIÓN: aparentemente solo funcionaría para la column = NULL , no para la columna = columna:

 t=# with s as (select null::int a, null::int b) select a <> b from s; ?column? ---------- (1 row)

entonces la comparación más corta sería coalesce:

 t=# with s as (select null::int a, null::int b) select coalesce(a,b,0) = 0 from s; ?column? ---------- t (1 row)

IF(a.unitnum IS null AND b.unitnum IS null) THEN RAISE NOTICE 'unitum field is null in both a and b tables' ELSE RAISE NOTICE 'unitum field is not null in at least one a or b tables' END IF;