#1451 - Cannot delete or update a parent row: a foreign key constraint fails 問題的解決辦法

錯誤

SQL 查詢:

DELETE FROM `zmax_lang` WHERE CONVERT( `zmax_lang`.`lang` USING utf8 ) = 'fr' LIMIT 1

MySQL 返回： #1451 - Cannot delete or update a parent row: a foreign key constraint fails (`myreview/zmax_text`, CONSTRAINT `zmax_text_ibfk_1` FOREIGN KEY (`lang`) REFERENCES `zmax_lang` (`lang`)) 

以上是因為，改條記錄的某個欄位作為innodb的另外一個表的外鏈。而在刪除操作時會自動檢查外鏈。解決的辦法之一是，不檢查外鏈，只需將執行語句前加上下句即可：

SET FOREIGN_KEY_CHECKS = 0; DELETE FROM `zmax_lang` WHERE CONVERT( `zmax_lang`.`lang` USING utf8 ) = 'fr' LIMIT 1