Unique Order Number

Learn to avoid the redundancy of rows.

Delete the wrong order

Let’s first delete the wrong order:

1 mysql> delete from orders where id = 2;
2 Query OK, 1 row affected (0.01 sec)
3
4 mysql> select * from orders;
5 +----+--------------+---------------------+-------------+
6 | id | order_number | ordered_at          | customer_id |
7 +----+--------------+---------------------+-------------+
8 |  1 | ABC001       |
...
Access this course and 1400+ top-rated courses and projects.