对同一表的列实施外键约束

How to enforce a constraint of foreign key on columns of same table in SQL while entering values in the following table:

员工:

• empid 编号，
• 经理编号(必须是现有员工)

推荐答案

CREATE TABLE TABLE_NAME (
    `empid_number`    int     (  11) NOT NULL auto_increment,   
    `employee`        varchar ( 100) NOT NULL               ,
    `manager_number`  int     (  11) NOT NULL               ,
     PRIMARY KEY  (`empid_number`),
     CONSTRAINT `manager_references_employee`
     FOREIGN KEY (`manager_number`) REFERENCES (`empid_number`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

希望对你有帮助！