我有下表学生：
Id FirstName LastName State Index Year Course1 Course2 Course3 Course4 Course5
622 Student622 LastName622 State17 62200 2 54 47 68 67 50
623 Student623 LastName623 State16 62300 3 17 99 37 99 32
624 Student624 LastName624 State2 62400 4 8 71 11 58 86
625 Student625 LastName625 State1 62500 2 39 75 33 77 17
626 Student626 LastName626 State15 62600 3 11 3 4 70 72
627 Student627 LastName627 State13 62700 2 84 77 65 62 76
628 Student628 LastName628 State13 62800 4 87 18 19 4 75
629 Student629 LastName629 State10 62900 2 96 67 14 97 31
课程1、2、3、4、5中的数字是外键值，它们引用以下课程表的ID：
Id Name ProfessorId
1 Course 1 8
2 Course 2 14
3 Course 3 4
4 Course 4 3
5 Course 5 6
6 Course 6 2
7 Course 7 14
8 Course 8 4
9 Course 9 5
如何编写脚本，以便在我执行而不是外键编号时有课程名称？有什么想法吗？
答案 0 :(得分：0)
您可以为每个课程ID左加入“课程”表。
SELECT
s.Id, s.FirstName, s.LastName, s.State, s.[Index], s.[Year],
c1.Name as Course1Name,
c2.Name as Course2Name,
c3.Name as Course3Name,
c4.Name as Course4Name,
c5.Name as Course5Name
FROM Student s
LEFT JOIN Courses c1 ON c1.Id = s.Course1
LEFT JOIN Courses c2 ON c2.Id = s.Course2
LEFT JOIN Courses c3 ON c3.Id = s.Course3
LEFT JOIN Courses c4 ON c4.Id = s.Course4
LEFT JOIN Courses c5 ON c5.Id = s.Course5
由于所有这些都是LEFT JOIN的，因此将返回所有Student的记录。
即使某些课程ID未被填写。