This query is used to show all underlivered orders with their ETA for a customer.

\begin{lstlisting}
SELECT
    orderID,
    order_date,
    DATE_FORMAT(ADDDATE(order_date, INTERVAL 15 DAY), "%Y-%m-%d") AS ETA
FROM orders
INNER JOIN customer ON orders.customerID = customer.customerID
WHERE customer.customerID = 1 AND orders.delivery_date IS NULL
ORDER BY order_date;
\end{lstlisting}