Question

So I have 2 tables.

table 1:

ID  CUST_NO
1   51555
2   51556
3   51111
4   44444
5   54878
6   13548

and table 2:

ID  CUST_NO
1   51555
2   51556
3   31333
4   97948
5   65488
6   14648
.   .....

I know I can use union to get the CUST_NO’s that appear in both tables. However, I need to get the list of CUST_NO’s that appear in table 1, but not in table 2.

So a result for this should be

51111
44444
54878
13548

I bet this is really easy but I just can’t use my head right now, any thoughts?

Answer 1

select t1.CUST_NO
from Table1 t1
left outer join Table2 t2 on t1.CUST_NO = t2.CUST_NO
where t2.CUST_NO is null