Set Membership

1. We use the in and not in operations for set membership.

    select distinct cname
   
   		 from borrower
   
   		 where cname in
   
   		 		 		 		 		 (select cname
   	from account
   	where bname=``SFU'')
   
   

2. Note that we can write the same query several ways in SQL.
3. We can also test for more than one attribute:

    select distinct cname
   
   		 from borrower, loan
   
   		 where borrower.loan# = loan.loan#
   and bname=``SFU''
   
   		 		 		 		 		 and (bname, cname) in
   
   		 		 		 		 		 (select bname, cname
   from account, depositor where depositor.account# = account.account#)
   
   

   This finds all customers who have a loan and an account at the SFU branch in yet another way.

4. Finding all customers who have a loan but not an account, we can use the not in operation.