how to add composite unique to a column in the table mysql

mysql, phpmyadmin

Solution

ALTER TABLE my_table ADD UNIQUE KEY (user_id, deal_type, deal_id);

Problem

I have a table: - `user_id int Composite Unique (deal_id + user_id+deal_type)`. - `deal_id int` - `deal_type varchar`. - `created_on datetime`. This is my table. I want to create a composite unique on the `user_id` column so that a single user can have only unique `deal_id` for each `deal_type`. How to make composite unique for in mysql phpmyadmin.

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