INSERT INTO mysql时的唯一值

Question

I have the following table in mysql:

    CREATE TABLE `kampbs` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `user` varchar(20) COLLATE utf8_danish_ci DEFAULT NULL,
 `k1` varchar(1) COLLATE utf8_danish_ci DEFAULT NULL,
 `k1r` varchar(10) COLLATE utf8_danish_ci DEFAULT NULL,
 `k2` varchar(1) COLLATE utf8_danish_ci DEFAULT NULL,
 `k2r` varchar(10) COLLATE utf8_danish_ci DEFAULT NULL,
 `k3` varchar(1) COLLATE utf8_danish_ci DEFAULT NULL,
 `k3r` varchar(10) COLLATE utf8_danish_ci DEFAULT NULL,
 `week` int(2) DEFAULT NULL,
 `grp` varchar(11) COLLATE utf8_danish_ci DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_danish_ci

I have a form, that INSERT INTO the fields in the database, but it should only be possible to insert once a week pr user. So it should check if the column 'user' and 'week' are unique together. Make sense? :/

Let's say the user 'freak' submit in week 13, he shouldn't be able to submit once again in week 13.

I use the following $sql:

$sql = "INSERT INTO kampbs(user, k1, k1r, k2, k2r, k3, k3r, week, grp) VALUES('$username', '$k1', '$k1r', '$k2', '$k2r', '$k3', '$k3r', '$week', '$grp')";

Answer 1

You can add a constraint to your table, so that the user / week couple is forced to be unique

ALTER TABLE `kampbs` ADD UNIQUE `unique_index`(`user`, `week`);