Question

I have two tables. First Table is a batch table that contain comma separated student id in field “batch”

batch
--------------
id      batch 
--------------
1       1,2     
2       3,4

Second Table is marks

marks
----------------------
id  studentid   subject     marks
1     1         English     50
2     2         English     40
3     3         English     70
4     1         Math        65
5     4         English     66
6     5         English     75
7     2         Math        55

How we can find those students of first batch id =1 who have scored more than 45 marks in English without using sub query.

Problem i found to get this done using a single query is that we can not use IN as an association operator in JOIN statement

What changes are required in below query to make it work?

SELECT * FROM batch
INNER JOIN marks ON marks.studentid IN(batch.batch) where batch.id = 1

Answer 1

SELECT  m.studentId
FROM    batch b
JOIN    marks m
ON      FIND_IN_SET(m.studentId, b.batch)
        AND m.subject = 'English'
GROUP BY
        m.studentId
HAVING  SUM(marks) > 45