php - 如何使多个列在同一个表中唯一

Question

ALTER TABLE  `registered` CHANGE  `Email_ID` UNIQUE KEY ( Email_ID) ) ;

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'UNIQUE KEY ( Email_ID )' at line 1

Answer 1

基本查询应该是这样的:

ALTER TABLE `test1`
  ADD UNIQUE KEY (`id`),
  ADD UNIQUE KEY `code` (`code`),
  ADD KEY `other` (`other`);

用于单独的唯一键。

组合键如下所示:

ALTER TABLE `test2`
  ADD UNIQUE KEY `id_code` (`id`, `code`),
  ADD KEY `other` (`other`);

(注:MySQL代码由phpmyadmin生成)