SQL find the codes that have no value. Multiple codes and null values.

What database product and version?

T-SQL and it's a temp table of a left join ordered by codes

Please explain this logic:
  count(case when value is null then 1 end) =   count(code)
It seams to me if code has any NULL value it will fail so I will try it ...thanks

I group by 'code'.

First half counts the codes that have a null values.
Second half counts the codes overall

When those counts are equal, then that code has ALL null values and it is returned.

worked like a charm! Thanks for getting me pat the mental block...