使用外键加入表

Question

学生表：

(student_id(PK),student_name,subject_enrolled(FK))

教师表：

(teacher_id(PK),teacher_name,subject_teaches(FK))

主题表：

(subject_id(PK),subject_name)

如何为此设置正确的JOIN TABLES查询：

Student_id,teacher_name- multiple names 
(resulted from same subject_enrolled and subject_teaches)

谢谢你们！

Answer 1

SELECT * FROM students AS st
LEFT JOIN subjects AS su ON su.subject_id = st.subject_enrolled
LEFT JOIN teachers AS t ON su.subject_id = t.subject_teaches

Answer 2

试试这个

Select students.student_id,GROUP_CONCAT(teachers.teacher_name)
FROM students
JOIN teachers ON teachers.subject_teaches = students.subject_enrolled
GROUP BY students.student_id

SQL Fiddle Demo