如何在SQL中加入5个以上的表？

Question

我想用SQL连接多个表。 这是我的表结构：

table 1: akdhis_mahasiswamagister (ID, MahasiswaID, NIM, MayorID, TahunMasuk)
table 2: akdmst_mayor(ID, DepartemenID)
table 3: ipbmst_departemen(ID, FakultasID, DepartmenName)
table 4: ipbmst_fakultas(ID, FacultyName)
table 5: ipbmst_orang(ID, Name, NIMS2Key)
table 6: akdhis_kelanjutanstudi(ID, NIM, IPK)

我想创建＆＃34;一个视图表＆＃34;加入此查询：

CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `aIPK` AS select 
`ipbmst_fakultas`.`Kode` AS `Fakultas`,
`ipbmst_departemen`.`Kode` AS `Departemen`,
`akdmst_mahasiswamagister`.`NIM` AS `NIM`,
`akdmst_mahasiswamagister`.`TahunMasuk` AS `TahunMasuk`,
 `akdhis_kelanjutanstudi`.`IPK` AS `IPK`
from (((((`akdmst_mahasiswamagister` left join `akdmst_mayor` on((`akdmst_mahasiswamagister`.`MayorID` = `akdmst_mayor`.`ID`))) 
left join `ipbmst_departemen` on((`akdmst_mayor`.`DepartemenID` = `ipbmst_departemen`.`ID`))) 
left join `ipbmst_fakultas` on((`ipbmst_departemen`.`FakultasID` = `ipbmst_fakultas`.`ID`))) 
left join `ipbmst_orang` on((`akdmst_mahasiswamagister`.`NIM` = `ipbmst_orang`.`NIMS2Key`))) 
left join `akdhis_kelanjutanstudi` on((`akdhis_kelanjutanstudi`.`NIM` = `ipbmst_orang`.`NIMS2Key`)))
WHERE IPK IS NOT NULL

order by NIM
LIMIT 100;

但是，当我尝试运行它时，结果是空的结果。我该怎么做才能解决这个问题？三江源