Question

我需要帮助来查询一个查询，该查询会拉出一个具有相同条目的条目。教师可以选择任何科目进行教学，学生可以选择任何科目进行教学。需要找一位选择教授同一学科组合的教师。

Table Student

id name
1  x
2  y

Table student_Subjects

id subject_id student_id
1  1          1
2  2          1
3  1          2

Teacher

id name
1  tx
2  ty

Table teacher_subjects

id subject_id teacher_id
1  1          2
2  2          2
3  1          1

Subject

id name
1  English
2  Maths

现在需要找一位选择与学生x教授相同科目的老师。

Answer 1

试试这个

SELECT GROUP_CONCAT(subject_id ORDER BY subject_id) as teacher_concat ,teacher_id
       FROM teacher_subjects 
       GROUP BY teacher_id 
       HAVING teacher_concat IN
                    (SELECT group_concat(subject_id ORDER BY subject_id)
                     FROM student_subjects GROUP BY student_id)

查找具有相同条目的条目有很多

1 个答案: