我的表结构是：
Student:
ID Name From
1 student A England
2 student B China
3 student C USA
Subject:
ID id_student Subject
1 1 Maths
2 1 Physics
3 2 English
4 3 Physics
5 4 History
我想让主表（A）中的所有数据和子表（B）中的所有have id_A行在网格表中显示如下：
ID Student Subject
1 student_A Maths, Physics
2 student_B English
3 student_C Physics, History
我想知道如何选择数据？
最佳答案
您可以使用GROUP_CONCAT：
SELECT t1.ID, t1.Name, GROUP_CONCAT(t2.Subject)
FROM Student AS t1
LEFT JOIN Subject AS t2 ON t1.ID = t2.id_student
GROUP BY t1.ID, t1.Name