ERROR 1022 (23000): Can‘t write; duplicate key in table ‘test4‘:在为"test4"表设置外键时.外键名与已有的外键名重复;代码如下,注意加粗部分
错误代码:
mysql> create table test4(
-> id int,
-> cp_name varchar(32),
-> constraint test_fk foreign key(cp_name) references student(name)
-> );
ERROR 1022 (23000): Can‘t write; duplicate key in table ‘test4‘
正确代码:
mysql> create table test4(
-> id int,
-> cp_name varchar(32),
-> constraint test1_fk foreign key(cp_name) references student(name)
-> );
Query OK, 0 rows affected (0.54 sec)
关于MySQL:ERROR 1022 (23000): Can't write; duplicate key in table 'test4'
原文：http://www.cnblogs.com/javk/p/4770217.html