query is not working correctly - mysql

Question

I have these tables:
single_user_has_university_has_course
single_user_users_id_user university_has_course_university_id_university university_has_course_course_id_course first_year_school last_year_school grade
1 1 1 2000 2001 15
And
university_has_course
university_id_university course_id_course
1 1 <<< I want to select this
15 1
1 3
15 3
The problem is that the query below return all rows where course_id_course = 1 but ignore theuniversity_id_university = 1`. Then, will return two rows.
query:
SELECT A.first_year_school, A.last_year_school, A.grade, U.university, C.course, T.type_course
FROM single_user_has_university_has_course A
INNER JOIN university_has_course Q
ON A.university_has_course_course_id_course = Q.course_id_course
INNER JOIN university U
ON Q.university_id_university = U.id_university
INNER JOIN course C
ON Q.course_id_course = C.id_course
INNER JOIN type_course T
ON C.type_course_id_type_course = T.id_type_course
AND A.single_user_users_id_user = ?

Answer 1

You are joining the last table to the previous joins on 2 constraints C.type_course_id_type_course = T.id_type_course AND A.single_user_users_id_user = ?. I think you want to write it as a WHERE clause. So replace your last line with:
WHERE A.single_user_users_id_user = ?
But you're not also trying to filter university_id_university = 1, so you may want to add it to the WHERE clause as well:
WHERE A.single_user_users_id_user = ? AND Q.university_id_university = ?