declare @e int
declare mycursor cursor
for 
select grade from sc
open mycursor
fetch next from  mycursor into @e
while(@@fetch_status=0)
begin
select
case 
  when @e<60 then '不及格'
  when @e>=60 and @e<70 then '及格'
  when @e>=70 and @e<80 then '中'
  when @e>=80 and @e<90 then '良'
  when @e>=90 and @e<=100 then '优'
end
deallocate mycursor