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

Question

I have a table:

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

Now I want to make the columns user

Answer 1

If You are creating table in mysql then use following :

create table package_template_mapping (
mapping_id  int(10) not null auto_increment  ,
template_id int(10) NOT NULL ,
package_id  int(10) NOT NULL ,
remark      varchar(100),
primary key (mapping_id) ,
UNIQUE KEY template_fun_id (template_id , package_id)
);