錯誤代碼1833 Cannot change column used in a foreign
ALTER TABLE server_list MODIFY COLUMN server_lip CHAR(25);
報錯信息:
1 queries executed, 0 success, 1 errors, 0 warnings
查詢:alter table server_list modify column server_lip char(25)
錯誤代碼: 1833
Cannot change column ‘server_lip‘: used in a foreign key constraint ‘server_history_ibfk_1‘ of table ‘OMServer.server_history‘
原因:server_list表中的server_lip字段為server_history表的外鍵,server_history建表語句:
CREATE TABLE server_history
(ID
int(11) NOT NULL AUTO_INCREMENT COMMENT ‘主鍵ID‘,history_id
int(11) NOT NULL COMMENT ‘事件ID‘,history_ip
char(15) NOT NULL COMMENT ‘事件IP地址‘,history_user
char(15) NOT NULL COMMENT ‘事件用戶名‘,history_datetime
db_datetime
timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT ‘入庫時間‘,history_command
char(255) NOT NULL COMMENT ‘事件命令‘,PRIMARY KEY (
ID
),KEY
history_ip
(history_ip
),CONSTRAINT
server_history_ibfk_1
FOREIGN KEY (history_ip
) REFERENCES server_list
(server_lip
)) ENGINE=InnoDB AUTO_INCREMENT=27 DEFAULT CHARSET=utf8 COMMENT=‘操作事件表‘
解決步驟:
1.鎖表
LOCK TABLES server_history WRITE,server_list WRITE;
2.查看是否被鎖
4.解除server_history表外鍵約束
ALTER TABLE server_history DROP FOREIGN KEY server_history_ibfk_1;
5.更改server_list表server_lip字段長度
ALTER TABLE server_list MODIFY COLUMN server_lip CHAR(25);
查看表結構發現已完成字段長度更新
6.新增server_history表外鍵約束
ALTER TABLE server_history
ADD CONSTRAINT server_history_ibfk_1
FOREIGN KEY (history_ip
) REFERENCES server_list
(server_lip
);
7.解除鎖定
UNLOCK TABLES;
錯誤代碼1833 Cannot change column used in a foreign