编写一个存储过程，包含一个输入参数，
   指定阶乘最大值，包含一个输出参数，返回阶乘的值。

create proc pro @n int,@sum int output
as
 declare @index int
 set @index=1
 set @sum=1

while(@index<=@n)
    begin
    set @sum=@sum*@index
    set @index=@index+1
    end
 
declare @sum int
exec pro 10,@sum output
select @sum as 结果为

4、编写一个存储过程，统计两个输入参数间能被整除
   的整数个数及这些整数的和，两个输入参数，两个输
   出参数。
 
create proc pron @n int,@m int,@sum int output,@total int output
as
set @sum=0
set @total=0
while (@n<=@m)
  begin
  if @n%13=0
    begin
    set @sum=@sum+@n
    set @total=@total+1
    set @n=@n+1
    end
  else
    set @n=@n+1
  end

declare @sum int,@total int 
exec pron 5,1000,@sum output,@total output
select @sum as 总和,@total as 总个数


参考

------解决方案--------------------

学生挂科率，和各个科目挂科率。表达式能贴出来。

------解决方案--------------------
--如果是查询
--学生考试挂科率
select m.id , m.student_name , cast(isnull(n.cnt, 0)*100.0 / m.cnt as decimal(18,2)) [挂科率] from
(select id , student_name , count(1) cnt from test_student group by id , student_name ) m
left join
(select id , student_name , count(1) cnt from test_student where core < 60 group by id , student_name ) n
on m.id = n.id

--各个科目的挂科率
select m.course_name , cast(isnull(n.cnt, 0)*100.0 / m.cnt as decimal(18,2)) [挂科率] from
(select course_name , count(1) cnt from test_student group by course_name) m
left join
(select course_name , count(1) cnt from test_student where core < 60 group by course_name) n
on m.course_name = n.course_name

--如果是要存储过程
--学生考试挂科率
create procedure my_proc1 as
begin
select m.id , m.student_name , cast(isnull(n.cnt, 0)*100.0 / m.cnt as decimal(18,2)) [挂科率] from
(select id , student_name , count(1) cnt from test_student group by id , student_name ) m
left join
(select id , student_name , count(1) cnt from test_student where core < 60 group by id , student_name ) n
on m.id = n.id
end

--各个科目的挂科率
crete procedure my_proc2 as
begin
select m.course_name , cast(isnull(n.cnt, 0)*100.0 / m.cnt as decimal(18,2)) [挂科率] from
(select course_name , count(1) cnt from test_student group by course_name) m
left join
(select course_name , count(1) cnt from test_student where core < 60 group by course_name) n
on m.course_name = n.course_name
end