How do I specify unique constraint for multiple columns in MySQL

0 votes

I have a table:

table votes (
    id,
    user,
    email,
    address,
    primary key(id),
);

Now I want to make the columns user, email, address unique (together).

How do I do this in MySql?

Aug 18, 2020 in PHP by kartik
• 37,530 points
977 views

1 answer to this question.

0 votes

Hello @kartik,

Use this:

ALTER TABLE `votes` ADD UNIQUE `unique_index`(`user`, `email`, `address`);

Hope it helps!!
Thank you!!

answered Aug 18, 2020 by Niroj
• 82,780 points

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