MySQL表rename導致的外鍵問題
阿新 • • 發佈：2019-03-03
show constrain orm 表結構 tab 查看表 into problem arch 背景：
由於zabbix監控的問題圖形展示很慢，對zabbix 庫的events表進行了清理，清理過程采用了原表rename成bak表，重建events表後，將備份表部分數據導入到新表中。
由於zabbix監控的問題圖形展示很慢，對zabbix 庫的events表進行了清理，清理過程采用了原表rename成bak表，重建events表後，將備份表部分數據導入到新表中。
後發現zabbix平臺無法報警，無法恢復報警，日誌類似報錯： 2315:20190301:104933.609 [Z3005] query failed: [1452] Cannot add or update a child row: a foreign key constraint fails (`zabbix`.`event_recovery`, CONSTRAINT `c_event_recovery_1` FOREIGN KEY (`eventid`) REFERENCES `events_bak20190225` (`eventid`) ON DELETE CASCADE) [insert into event_recovery (eventid,r_eventid,correlationid,c_eventid,userid) values (4242559,4242581,null,null,null),(4242561,4242580,null,null,null),(4242447,4242580,null,null,null);
原來rename後，關聯的外鍵表的約束竟然一並修改成了歸檔表的關聯。
處理方法如下：
查看哪些表建立外鍵時關聯了歸檔表
select distinct TABLE_NAME,CONSTRAINT_NAME,REFERENCED_TABLE_NAME from INFORMATION_SCHEMA.KEY_COLUMN_USAGE where TABLE_SCHEMA =‘zabbix‘ and CONSTRAINT_name != ‘PRIMARY‘ and REFERENCED_TABLE_NAME like ‘event%‘; +----------------+--------------------+-----------------------+ | TABLE_NAME | CONSTRAINT_NAME | REFERENCED_TABLE_NAME | +----------------+--------------------+-----------------------+ | acknowledges | c_acknowledges_2 | events | | alerts | c_alerts_2 | events | | alerts | c_alerts_5 | events | | event_recovery | c_event_recovery_1 | events | | event_recovery | c_event_recovery_2 | events | | event_recovery | c_event_recovery_3 | events | | event_tag | c_event_tag_1 | events_bak20190225 | | problem | c_problem_1 | events | | problem | c_problem_2 | events | +----------------+--------------------+-----------------------+
查看表結構：
show create table event_tag\G *************************** 1. row *************************** Table: event_tag Create Table: CREATE TABLE `event_tag` ( `eventtagid` bigint(20) unsigned NOT NULL, `eventid` bigint(20) unsigned NOT NULL, `tag` varchar(255) NOT NULL DEFAULT ‘‘, `value` varchar(255) NOT NULL DEFAULT ‘‘, PRIMARY KEY (`eventtagid`), KEY `event_tag_1` (`eventid`), CONSTRAINT `c_event_tag_1` FOREIGN KEY (`eventid`) REFERENCES `events_bak20190225` (`eventid`) ON DELETE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=utf8
修改外鍵約束：
alter table event_tag drop FOREIGN KEY c_event_tag_1;
alter table event_tag add FOREIGN KEY c_event_tag_1 (`eventid`) REFERENCES `events`(`eventid`) ON DELETE CASCADE;zabbix好多外鍵，下次清理數據直接刪除吧。
MySQL表rename導致的外鍵問題