Can you show me the number of customers?
select count ( distinct custid ) from accounts
how about the number of checking accounts?
select count ( * ) from checking
what's the lowest balance of a savings account?
select min ( balance ) from savings
who owns that account?
select t2.custid from accounts as t1 join savings as t2 on t1.custid = t2.custid order by t2.balance limit 1
what's the checking balance of that person?
select t2.balance from accounts as t1 join checking as t2 on t1.custid = t2.custid join savings as t3 on t1.custid = t3.custid order by t3.balance limit 1