添加外键约束语法:
ALTER+空格+TABLE+表明+ADD+CONSTRAINT+外键名+FOREIGN +KEY(外键字段)+空格+REFERENCES+表明(主键);
测试表1:
CREATE TABLE `test1` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`name` VARBINARY(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=INNODB DEFAULT CHARSET=utf8
测试表2:
CREATE TABLE `test2` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`name` VARCHAR(50) DEFAULT NULL,
`tid` INT(45) DEFAULT NULL,
PRIMARY KEY (`id`),
) ENGINE=INNODB DEFAULT CHARSET=utf8
执行关联语句:
ALTER TABLE test2 ADD CONSTRAINT tid FOREIGN KEY(id) REFERENCES test1(id);
来源:CSDN
作者:wangxuejava
链接:https://blog.csdn.net/wangxuejava/article/details/102659815