Need to find a pattern in SQL Data base and then write a query to delete the duplicate "NULL" Value
Assuming your table name is tab1, this should work.

delete tab1 
from tab1 t
join (select practice from tab1
        group by practice
        having count(1)&gt;1) sub
    on t.practice=sub.practice
where q1 is null
    and q2 is null
    and q3 is null
    and q4 is null 
    and ytd is null
    and avg is null