declare @a int
declare @sum int
set @sum=0

declare testcur cursor
for
 select sal from sawon
open testcur   /*커서로 데이터를 받아옴. */

fetch next from testcur  into @a
while ( @@fetch_status = 0 )
       begin
             set @sum = @sum + nullif( @a , 0 )
            fetch next from testcur  into @a
     end
print @sum

close testcur  /*커서의 내용을 비움 */
deallocate testcur

select sum(sal) from sawon