Yurttas/PL/DBL/oracle/F/01/Bank/a04.sql

 1REM
 2REM a04.sql
 3REM
 4REM Find the average balance of all depositors who live in `Harrison'
 5REM and have at least 3 accounts.
 6REM
 7
 8SELECT AVG(balance)
 9FROM Depositor, Customer
10WHERE Depositor.customername = Customer.customername
11  AND Customer.customercity = 'Harrison'
12GROUP BY Depositor.customername
13HAVING COUNT(accountnumber) >= 3;