triple_join.sql

SELECT * FROM CUSTOMERS, ORDERS, ORDER_ITEMS
WHERE CUSTOMERS.CUSTOMER_ID = ORDERS.CUSTOMER_ID and ORDERS.ORDER_ID = ORDER_ITEMS.ORDER_ID;

SELECT CUSTOMERS.FNAME, CUSTOMERS.LNAME, count(distinct ORDERS.ORDER_ID) Orders, sum(ORDER_ITEMS.UNIT_PRICE * ORDER_ITEMS.QUANTITY) FROM CUSTOMERS, ORDERS, ORDER_ITEMS
WHERE CUSTOMERS.CUSTOMER_ID = ORDERS.CUSTOMER_ID and ORDERS.ORDER_ID = ORDER_ITEMS.ORDER_ID group by CUSTOMERS.FNAME, CUSTOMERS.LNAME order by 4 desc;