檢索值

Question

每個Student和Teacher有自己UNIQUEUserID
是否有可能在一次檢索來自三個表中的值？ 這樣：它會顯示UserID擁有的每個Student或Teacher？ 我試過下面的查詢，但它不工作：

SELECT u.UserID, StudentID, TeacherID 
FROM User u 
INNER JOIN (SELECT * FROM Student, Teacher) ss 
ON u.UserID = ss.UserID 

Answer 1

也許是這樣的：用左

SELECT u.UserID, S.StudentID, T.TeacherID 
from User U 
left join Student S on S.UserID = u.UserID 
left join Teacher T on T.UserID = U.UserID