How to Generate a Sequential Column Based on a Foreign Key in MySQL?

Adding a Sequence Column Based on Foreign Key

To achieve a sequential column based on a foreign key in MySQL, you can employ the following SQL approach:

Create a trigger before inserting into the table:

Retrieve the maximum existing sequence number for the corresponding foreign key:

Assign the calculated sequence number to the new row:

By utilizing this trigger, each newly inserted row will be assigned a sequence number that increments for the specified foreign key, as illustrated in the example provided.

The above is the detailed content of How to Generate a Sequential Column Based on a Foreign Key in MySQL?. For more information, please follow other related articles on the PHP Chinese website!