BigQuery SQL Exclusion NOT IN empty results

Question

I\'m having problems with this not returning any values. There are accounts in the database that match this criteria. Somewhat confused why they aren\'t being returned. Any sugg

Answer 1

Ensure you're referencing the field you don't want to be present in the subquery result:

select accountid from `table1` 
where accountid not in (select accountid from `table1` where action != "Action8")

Answer 2

Do not use not in. Semantically, it is counter-intuitive. If any values in the subquery are NULL, then no rows are returned.

Use not exists instead;

select t1.accountid
from `table1` t1
where not exists (select 1
                  from table1 tt1
                  where tt1.accountid  = t1.accountid and
                        tt1.action <> 'Action8'
                 );

Or use group by and having:

select t1.accountid
from table1 t1
group by t1.accountid
having sum(case when action = 'Action8' then 1 else 0 end) = 0;