存储过程复习题.doc
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(一)存储过程
1、对学生课程数据库，编写2个存储过程，分别完成下面功能：
? ?1）统计某一门课的成绩分布情况，即按照各分数段统计人数，要求使用游标。
create proc TotalByCnoNum
(
@cno varchar(6)
)
as
begin
declare @num1 int ,@num2 int, @num3 int,@num4 int ,@num5 int,@grade int,@cname char(20)
select @num1=0,@num2=0,@num3=0,@num4=0,@num5=0
declare cur_cno cursor for select grade from sc where cno=@cno
open cur_cno
fetch next from cur_cno into @grade
while @@fetch_status=0
begin
if @grade between 90 and 100
set @num1=@num1+1
else if @grade between 80 and 89
set @num2=@num2+1
else if @grade between 70 and 79
set @num3=@num3+1
else if @grade between 60 and 69
set @num4=@num4+1
else
set @num5=@num5+1
fetch next from cur_cno into @grade
end
close cur_cno
deallocate cur_cno
select @cname=cname from course where cno=@cno
print 课程：+@cname
print 分数段人数统计
print ==========================
print 90-100 : +convert(varchar(3),@num1)
print 80-89 : +convert(varchar(3),@num2)
print 70-79 : +convert(varchar(3),@num3)
print 60-69 : +convert(varchar(3),@num4)
print 不及格: +convert(varchar(3),@num5)
print ==========================
end
执行以下语句，显示课程号为3的成绩情况：
exec TotalByCnoNum 3
运行结果如下：
? ?2）将学生选课成绩从百分制改为等级制（即A、B、C、D、E五级）。
create proc ChangeGrade
as
begin
declare @dj char(1),@cname char(20),@cno char(6),@sno char(9), @grade int
declare cur_cno cursor for select grade,cno,sno from sc
open cur_cno
fetch next from cur_cno into @grade,@cno,@sno
print 学号 课程号 等级
print ==========================
while @@fetch_status=0
begin
if @grade between 90 and 100
set @dj=A
else if @grade between 80 and 89
set @dj=B
else if @grade between 70 and 79
set @dj=C
else if @grade between 60 and 69
set @dj=D
else
set @dj=E
print @sno+ +@cno+ +@dj
print --------------------------
fetch next from cur_cno into @grade,@cno,@sno
end
print =========================
close cur_cn
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