count only if field is filled : I have a question about an sql query i want to make. Supose i have an column with the follow values in table: school with column: grades.

     SUI grades | Score
      2  9          2
      2  9          
      5  4          1
      5  4          1
      5  4
      6  1          1
      6  1          

Now i wan't an output where it groups the SUI that counts grades only if Score is filled. So my output will be:

    SUI Count 
     2    1
     4    2
     6    1

