Mysql表创建外键报错解决方案

数据库表A：

CREATE TABLE task_desc_tab(  id INT(11) PRIMARY KEY NOT NULL COMMENT '自增主键' AUTO_INCREMENT,  <strong>taskname</strong> VARCHAR(200) NOT NULL COMMENT '任务名字',  sqlname VARCHAR(20) NOT NULL COMMENT 'sql文件名字',  params VARCHAR(5000) NOT NULL COMMENT '任务参数,格式为一个JSON字符串',  updatetime TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT '更新时间',  detail VARCHAR(3000) COMMENT '任务一些描述信息,只是备注信息作用') ENGINE = InnoDB DEFAULT CHARSET = utf8;

CREATE TABLE exec_plan_tab(  id INT(11) PRIMARY KEY NOT NULL AUTO_INCREMENT,  <strong>taskname</strong> VARCHAR(200) NOT NULL,  startdate DATE NOT NULL,  enddate DATE NOT NULL,  updatetime TIMESTAMP DEFAULT CURRENT_TIMESTAMP,  CONSTRAINT exec_plan_tab_task_desc_tab_taskname_fk FOREIGN KEY (taskname) REFERENCES task_desc_tab (taskname)) ENGINE = InnoDB DEFAULT CHARSET = utf8;

[2018-07-19 15:02:29] [HY000][150] Create table 'daxin/#sql-5d_30' with foreign key constraint failed. There is no index in the referenced table where the referenced columns appear as the first columns.
[2018-07-19 15:02:29] [HY000][1215] Cannot add foreign key constraint
[2018-07-19 15:02:29] [HY000][1215] Cannot add foreign key constraint　

经过排查找到问题原因：表A中的taskname必须使用UNIQUE字段修饰，这样保证记录唯一性，当表B参考时候不会出现歧义。

更多相关文章

随机推荐