Question

mysql参照表和被参照表是本身问题：Cannot add or update a child row: a foreign key constraint fails

建表：

Course
CREATE TABLE Course (
Cno Char(4) PRIMARY KEY,
Cname Char(40),
Cpno Char(4),
Ccredit Int,
FOREIGN KEY (Cpno) REFERENCES Course(Cno)
);

插入数据：

INSERT INTO Course VALUES('2', ' 数学', '',2);
INSERT INTO Course VALUES('1','数据库','5',4);
INSERT INTO Course VALUES('3', 信息系统', '1',4);
INSERT INTO Course VALUES('4', ' 操作系统', '6',3);
INSERT INTO Course VALUES('5', ' 数据结构', '7',4);
INSERT INTO Course VALUES('6', '数据处理', '',2);
INSERT INTO Course VALUES('7', ' PASCAL语言', '6',4);

就会因为因外键Cpno和主键Cno顺序问题出错，怎么解决~
谢谢………………

Answer 1

1.将原表分为两个表，即把Cpno和Cno分开，先填Cno再填Cpno
2。先把Cpno都空着，吧Cno填好了再填Cpno