This is how i goes

Select
Student.stud_id,
Student.stud_name,
Max(subject.marks)
from Student, subject, stud_sub
where sum(marks)<
( Select Max(sum(marks)) from student, subject,...

If you can type all the column names you can get the default avatar_id(1)

Try this :

SELECT members.*,ifnull(avatar_id,1) FROM members
left outer join avatars
on...

select user from mysql.user where user=' ';

you should have access to mysql DB to execute the query