有以下sql
SELECT DISTINCT questionid,questiontype
FROM x2_questions AS questions,x2_quest2knows AS quest2knows
WHERE find_in_set(quest2knows.qkknowsid,:knowsid)
AND quest2knows.qktype = 0
AND quest2knows.qkquestionid = questions.questionid
AND questions.questionstatus = 1
ORDER BY questionparent asc,questionsequence 運行時提示錯誤信息
Expression #1 of ORDER BY clause is not in SELECT list, references column 'pe6.questions.questionparent' which is not in SELECT list; this is incompatible with DISTINCT
錯誤原因：
mysql5.7版本中，如果DISTINCT和order by一起使用將會報3065錯誤，sql語句無法執行。這是由於5.7版本語法比之前版本語法要求更加嚴格導致的。
解決方案：
修改mysql的安全模式,即sql_mode。
步驟：
1.mysql終端中輸入下面命令，查看相關配置信息
show variables like '%sql_mode%';
默認情況下可以看到如下信息
| sql_mode | ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
2.設置sql_mode去掉ONLY_FULL_GROUP_BY
推薦在mysql的配置文件my.cnf文件(linux)/my.ini文件(window) 的mysqld中增加或者修改sql_model配置選項
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
3.重啓mysql生效
4.驗證
在mysql終端中輸入下面命令，查看結果。
show variables like '%sql_mode%';