關於mysql 5.7版本“報[Err] 1093 - You can't specify target table 'XXX' for update in FROM clause”錯誤的bug
阿新 • • 發佈:2017-09-21
title _id fma xxx tps ice sql each targe
不同於oracle和sqlserver,mysql並不支持在更新某個表的數據時又查詢了它,而查詢的數據又做了更新的條件,因此我們需要使用如下的語句繞過:
UPDATE teaching_department SET code_year = 2017, notice_code = (SELECT a.code + 1 FROM (SELECT MAX(notice_code) code FROM teaching_department WHERE department_id = 6284 and code_year = 2017) a) WHERE id = 106;
本地測試是通過的,但是在上到測試環境的時候,發現還是會報如下錯誤:
[SQL] UPDATE teaching_department SET code_year = 2017, notice_code = (SELECT a.code + 1 FROM (SELECT MAX(notice_code) code FROM teaching_department WHERE department_id = 6284 and code_year = 2017) a) WHERE id = 106; [Err] 1093 - You can‘t specify target table ‘teaching_department‘ for update in FROM clause
對比版本發現,本地是5.6.25,測試環境是5.7.10,版本高的反而不支持了。只能改用另一種方式實現:
UPDATE teaching_department, (SELECT MAX(notice_code) code FROM teaching_department WHERE department_id = 6284 AND code_year = 2017) AS t SET code_year = 2017, notice_code = t.code + 1 WHERE id = 7
這種寫法在各版本都是支持的。語法見UPDATE Syntax
後來發現,這是mysql 5.7.6版本出現的一個bug,並且在5.7.11版本中修復了。參考
關於mysql 5.7版本“報[Err] 1093 - You can't specify target table 'XXX' for update in FROM clause”錯誤的bug