我有2张桌子：
表1：时间表
monday tuesday wednesday
------ ------- ---------
18 15 2
10 8 6
表2：对象
subject_id subject_name
---------- ------------
18 maths
10 history
8 english
结果应如下所示：
monday tuesday wednesday
------- -------- ---------
maths phy phy
history history phy
english chem phy
我该怎么做呢 ？
最佳答案
SELECT ms.subject_name as moday,
ts.subject_name as tuesday,
ws.subject_name as wednesday
FROM timetable t
INNER JOIN subjects ms ON t.monday = ms.subject_id
INNER JOIN subjects ts ON t.tuesday = ts.subject_id
INNER JOIN subjects ws ON t.wednesday = ws.subject_id