my-guitar-shop-database-exersices/Exercise_4.-6.sql

SELECT 
    email_address, order_id, order_date
FROM
    customers c
        JOIN
    orders o ON c.customer_id = o.customer_id
WHERE
    order_date = (SELECT 
            MIN(order_date)
        FROM
            orders
        WHERE
            customer_id = o.customer_id);