Question

i have table T1

ID
1
2
3

and table T2

ID    HISTORY
1       1
1       1
2       1
2       0 

I must select from T1 all records which does not exist in T2 or exists but all records are in history (history flag =1)

So for this my result will be

1
3

What is the correct SQL query for this?
Thanks

Answer 1

try this:

select * from T1
where ID not in(select ID from T2 where HISTORY_FLG!=1)

SQL Fiddle demo