How do I specify unique constraint for multiple columns in MySQL? -

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i have table:

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

now want make columns user, email, address unique (together).

how do in mysql?

  • of course example just... example. please don't worry semantics.

alter table `votes` add unique `unique_index`(`user`, `email`, `address`);

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