创建表时直接设置:

DROP TABLE IF EXISTS `student`;

CREATE TABLE `student` (

  `stu_id` int(11) NOT NULL AUTO_INCREMENT,

  `name` varchar(255) DEFAULT NULL,

  PRIMARY KEY (`stu_id`),

  UNIQUE KEY `UK_student_name` (`name`) 

) ENGINE=InnoDB AUTO_INCREMENT=12 DEFAULT CHARSET=utf8;

 

 

创建唯一索引:

create unique index UK_student_name on student (name);

 

建表后添加约束:

alter table student add constraint uk_student_name unique (name);