select查询从主表获取数据和子表中的所有值？

Question

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

我想获取主表（A）中的所有数据以及子表（B）中的所有行都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？

Answer 1

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