使用SQL連接四個表

Question

如何連接4個表並檢索有關一個ID（行）的信息？

這是我到目前爲止有：

Answer 1

根據您的意見，問題是，你必須使用相同的名稱，這樣的東東用別名數列：

SELECT Crs_Desc, Enrollment.Enrollme, Enrollment.Offer_No 
FROM Offerin, Course 
JOIN Enrollment ON Enrollment.Offer_No = Offering.Offer_No 
JOIN Student ON Student.Std_ID = Enrollment.Std_ID 

WHERE Enrollment.Std_ID = '103' 
GROUP BY Enrollment.Std_ID; 

如果該查詢做不解決你的問題，分享你的表格數據和預期結果

Answer 2

嘗試類似這樣的事情。

SELECT Student.Student_ID, Course.Crs_Desc, 
    Enrollment.Std_ID, Enrollment.Offer_No, 
    Offering.Offer_No 
    FROM Student 
     JOIN Enrollment 
      ON Student.Student_ID = Enrollment.Std_ID 
     JOIN Offering 
      ON Enrollment.Std_ID = Offering.Offer_No 
     JOIN Course 
      ON Offering.Offer_No = Course.CourseNo 
     WHERE Student_ID = '103'; 

此外，WHERE子句看起來可能是錯誤的。嘗試「WHERE Student_ID ='103';」

Answer 3

試試這個：

SELECT Student.Student_ID 
     ,Course.Crs_Desc 
     ,Enrollment.Std_ID 
     ,Enrollment.Offer_No 
     ,Offering.Offer_No 
    FROM Student 
     LEFT JOIN Enrollment 
      ON Student.Student_ID = Enrollment.Std_ID 
     LEFT JOIN Offering 
      ON Enrollment.Std_ID = Offering.Offer_No 
     LEFT JOIN Course 
      ON Offering.CourseNo = Course.CourseNo 
     WHERE Student.Student_ID = '103';