Bonus: Join All The Things


    SELECT s.customer_id, TO_CHAR(s.order_date, 'YYYY-MM-DD') AS order_date, m.product_name, m.price,
    CASE WHEN mem.join_date <= s.order_date THEN 'Y'
    	ELSE 'N' END AS member
    FROM dannys_diner.sales AS s
    JOIN dannys_diner.menu AS m
    ON s.product_id=m.product_id
    LEFT JOIN dannys_diner.members AS mem
    ON s.customer_id=mem.customer_id
    ORDER BY customer_id, order_date;



| customer_id | order_date | product_name | price | member |
| ----------- | ---------- | ------------ | ----- | ------ |
| A           | 2021-01-01 | sushi        | 10    | N      |
| A           | 2021-01-01 | curry        | 15    | N      |
| A           | 2021-01-07 | curry        | 15    | Y      |
| A           | 2021-01-10 | ramen        | 12    | Y      |
| A           | 2021-01-11 | ramen        | 12    | Y      |
| A           | 2021-01-11 | ramen        | 12    | Y      |
| B           | 2021-01-01 | curry        | 15    | N      |
| B           | 2021-01-02 | curry        | 15    | N      |
| B           | 2021-01-04 | sushi        | 10    | N      |
| B           | 2021-01-11 | sushi        | 10    | Y      |
| B           | 2021-01-16 | ramen        | 12    | Y      |
| B           | 2021-02-01 | ramen        | 12    | Y      |
| C           | 2021-01-01 | ramen        | 12    | N      |
| C           | 2021-01-01 | ramen        | 12    | N      |
| C           | 2021-01-07 | ramen        | 12    | N      |

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