Cross Joins

-- Finding Orders Placed By George: 2 Step Process

SELECT id FROM customers WHERE last_name='George';
SELECT * FROM orders WHERE customer_id = 1;

-- Finding Orders Placed By George: Using a subquery

SELECT * FROM orders WHERE customer_id =
    (
        SELECT id FROM customers
        WHERE last_name='George'
    );

-- Cross Join Craziness

SELECT * FROM customers, orders;