MySQL - Unique foreign key

Question

I have to make one of the foreign keys unique. The problem is, I am getting the following message from the phpMyAdmin:

The following indexes appear to be equal an         


        

Answer 1

For the future, if you want to make your foreign key unique, you can simply modify your foreign key column like this:

ALTER TABLE your_table
MODIFY COLUMN your_fk_column [INT, VARCHAR etc.][NOT NULL] UNIQUE;