Можете ли вы помочь мне построить этот запрос? кажется, что я всегда получаю дубликат с помощью group_concat

Привет мне нужна помощь о том, как удалить дубликаты в group_concat, я пытался использовать разные, но это также удалит дубликаты внутри базы данных, что не то, что я хочу.
мой запрос в php:

SELECT
students.*,
GROUP_CONCAT(
CONCAT(
'<td width=2% valign=top>',
quiz.Score,
'</td>'
)
Order by
Quiznumber SEPARATOR ''
) As qscore,
Avg(quiz.Score) As avgscore,
quiz.Subject_Code,
GROUP_CONCAT(
DISTINCT CONCAT(
'<td width=2% valign=top>',
recitation.Score,
'</td>'
)
Order by Recnumber SEPARATOR ''
) As rScore,
Avg(recitation.Score) As avgrscore,
recitation.Subject_Code,
Avg(assignments_projects.Score) As assscore,
assignments_projects.Subject_Code,
exam.Score,exam.Subject_Code,
Avg(attendance.Score) As attscore,
attendance.Subject_Code
FROM
students
LEFT JOIN
quiz
ON
students.Student_ID = quiz.Student_ID
LEFT JOIN
recitation
ON
students.Student_ID = recitation.Student_ID
LEFT JOIN
assignments_projects
ON
students.Student_ID = assignments_projects.Student_ID
LEFT JOIN
attendance
ON
students.Student_ID = attendance.Student_ID
LEFT JOIN
exam
ON
students.Student_ID=exam.Student_ID
WHERE
quiz.Subject_Code='$subjects'
AND quiz.Term='Prelim'
AND quiz.Section='$section'
AND  recitation.Subject_Code='$subjects'
AND  recitation.Term='Prelim'
AND recitation.Section='$section'
AND assignments_projects.Subject_Code='$subjects'
AND assignments_projects.Term='Prelim'
AND assignments_projects.Section='$section'
AND attendance.Subject_Code='$subjects'
AND attendance.Term='Prelim'
AND attendance.Section='$section'
AND exam.Subject_Code='$subjects'
AND exam.Term='Prelim' AND exam.Section='$section'
GROUP BY
Student_ID
ORDER BY
Last_Name