Unique Order Number
Explore how to ensure data integrity by creating a unique index on the order_number column in a MySQL table. Learn to delete incorrect entries, add unique constraints, and prevent duplicate orders in your database.
We'll cover the following...
We'll cover the following...
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 | 2016-09-09 08:34:55 | 1 |
9 +----+--------------+-----------