Which records aren't in list? Use static list as table or records

Hi!

A very silly question. I have a limited list of identifiers.
I want to know which one IS NOT in a table.

The
select * from theserecords where id not in (1, 5, 12, 33, 55)
isn't listing missing records... because they are missing... :-)

For example, a pseudo:
idlist = (1, 5, 12, 33, 55)
select id from idlist
where id not in (select id from theserecords)

The id list is a static string.

Now I can do this with temporary table - I create one, insert the ID-s and
run the select:

select id from temptable where id not in (select id from theserecords)

It would be nice if I can get the missing ID-s.

F.e:

select id from (
select 1 as id,
select 5 as id,
...
) where id not in (select id from theserecords)

or

select id from (
select split_string_to_records('1,2,3,4,5', ',') as id
) ...

Do you know any simple way to do this without stored proc or temp table?

Thank you!

B.W:
dd