MySQL还不支持限制&& in / all？

Posted 2021-04-09

我的查询如下：

 SELECT * FROM `C_Institute`
 WHERE `ID` IN
 (SELECT `instituteID` FROM `C_Faculty` WHERE `ID` 
 IN (SELECT `facultyID` FROM `C_EducationalGroup` WHERE `ID` 
 IN (SELECT `educationalGroupID` FROM `C_StudyField` WHERE `ID` 
 IN (SELECT `studyFieldID` FROM `b_PersonEmployment` WHERE `personID`=1 ORDER BY `startDate` limit 1) )));

但是mysql不支持子查询上的limit和in。我不知道怎么写这个查询。有人可以帮我吗？

提前致谢

答案

您可以重写此查询一系列连接：

SELECT c1.*
FROM C_Institute c1
INNER JOIN C_Faculty c2
    ON c1.ID = c2.instituteID
INNER JOIN C_EducationalGroup c3
    ON c2.ID = c3.facultyID
INNER JOIN C_StudyField c4
    ON c3.ID = c4.educationalGroupID
INNER JOIN b_PersonEmployment b
    ON c4.ID = b.studyFieldID
WHERE b.personID = 1
ORDER BY b.startDate
LIMIT 1;

另一答案

假设每个表中的ID指的是另一个表，那么，

试试这个让我知道：

select * from C_Institute c join C_Faculty f on c.ID=F.instituteID left join C_EducationalGroup e on f.ID=e.facultyID left join C_StudyField sf on e.ID=sf.educationalGroupID left join b_PersonEmployment p on sf.ID=p.studyFieldID where p.personID=1 order by p.startDate limit 1;  

此外，分享您的表格描述以获取更多线索

另一答案

谢谢你的所有答案。但我认为加入并不是解决这个问题的好方法。我通过两个查询完成它（可能不是好主意但比连接更好）：

SET @studyFieldID =(SELECT `studyFieldID` FROM `b_PersonEmployment` WHERE `personID`=1 ORDER BY `startDate` limit 1); 
SELECT * FROM `C_Institute`
 WHERE `ID` IN
 (SELECT `instituteID` FROM `C_Faculty` WHERE `ID` 
 IN (SELECT `facultyID` FROM `C_EducationalGroup` WHERE `ID` 
 IN (SELECT `educationalGroupID` FROM `C_StudyField` WHERE `ID`=@studyFieldID 
  )));