14、SQL基础整理（存储过程）

数据库—可编程性—存储过程

新建存储过程：

create proc firstproc

as

select *from fenshu

go

执行存储过程：

存储过程—右键—执行存储过程

declare @fanhuizhi  int

exec @fanhuizhi = firstproc

select ‘Return Value‘ = @fanhuizhi

return  value执行成功/失败的返回值（0为成功）

execute/exec firstproc

修改存储过程

alter proc firstproc

as

select yuwen,shuxue,yingyu,name from student,fenshu where student.code = fenshu.code

go

execute firstproc

查询多个表

create proc secondproc

as

begin

　　select*from student

　　select*from teacher

　　select*from fenshu

end

带子查询的查询过程

create proc threeproc

as

begin

　　declare @count int

　　select @count=count(*) from (select *from student where code = any(select code from fenshu where code in

　　(select code from student where MT = ( select code from teacher where name = ‘数一‘))and shuxue>80)

　　)as new

　　if @count> 3

　　　　print‘达标‘

　　else

　　　　print‘不达标‘

end

exec threeproc

带参数的查询过程

create proc fourthproc

@hello varchar(20),

@ercan varchar(20)—参数部分

as

begin

    print @hello+@ercan

end

go

exec fourthproc ‘helloworld‘,‘,你好世界！‘

复杂参数

create proc fifthproc

@name varchar(20)

as

begin

    declare @countjs int,@lesson varchar(20)

    select @countjs = COUNT(*)from teacher where name = @name

    if @countjs = 0

    begin

       print ‘没找到这个老师‘

    end

    else

    begin

    　　select @lesson = course from teacher where name = @name

    　　declare @count int

   　　 if @lesson = ‘语文‘

   　　　　 begin

　　　　　　　　select @count= count(*)from student where code = any(select code from fenshu where code in

　　　　　　　　(select code from student where CT = ( select code from teacher where name = @name))and yuwen>80)

   　　　　 end

   　　 else

   　　 if @lesson = ‘数学‘

    　　　　begin

      　　　　　　 select @count= count(*)from student where code = any(select code from fenshu where code in

      　　　　　　 (select code from student where MT = ( select code from teacher where name = @name))and shuxue>80)

    　　　　end

   　　 else

  　　  if @lesson = ‘英语‘

   　　　　 begin

      　　　　　　 select @count= count(*)from student where code = any(select code from fenshu where code in

       　　　　　　(select code from student where ET = ( select code from teacher where name = @name))and yingyu>80)

   　　　　 end

   　　 if @count>=3

   　　　　 print ‘达标‘

    　　else

    　　　　print ‘不达标‘

    end

end

go

exec fifthproc (@name=可忽略)‘数一‘

exec fifthproc ‘数‘

删除存储过程

drop proc 存储过程名

练习

------------输入学生的学号，看是否结业（三门课都超过分发优秀证书，有两门课或以上不及格不结业，有一门课不及格结业）------------

alter proc jieye

@xuehao int

as

begin

    declare @shuxue int

    declare @yuwen int

    declare @yingyu int

    declare @zongfen int

    select @shuxue = count(*) from fenshu where code=@xuehao and shuxue>80

    select @yuwen = count(*) from fenshu where code=@xuehao and yuwen>80

    select @yingyu = count(*) from fenshu where code=@xuehao and yingyu>80

    set @zOngfen= @shuxue+@yuwen+@yingyu

    if @zOngfen= 3

    print ‘优秀‘

    if @zOngfen= 2

    print ‘结业‘

    if @zongfen <2

    print ‘不结业‘

end

go

返回值

-----------输入一个数,使其+10返回------定义变量接收执行存储过程返回的值

create proc jisuan

@sum int（可以设默认值@sum int=10）

as

begin

    set @sum = @sum +10

    return @sum

end

declare @shu int

exec @shu = jisuan 2（把2改为default即可按照默认值的输出结果打印）

print @shu

---------返回总分的个数并打印出来-----------

create proc jieye2

@xuehao int

as

begin

    declare @shuxue int

    declare @yuwen int

    declare @yingyu int

    declare @zongfen int

    select @shuxue = count(*) from fenshu where code=@xuehao and shuxue>80

    select @yuwen = count(*) from fenshu where code=@xuehao and yuwen>80

    select @yingyu = count(*) from fenshu where code=@xuehao and yingyu>80

    set @zOngfen= @shuxue+@yuwen+@yingyu

    return @zongfen

end

declare @count int

exec @count = jieye2 1

print @count

return后面的存储过程将不再运行（放在if等句子里的例外）

练习

--输入一个数n，求n+n-1+……+1的和---

alter proc qiuhe

@n int

as

begin

    declare  @sum int =0

    while @n>=1

    begin

       set @sum = @n+@sum

       set @n = @n-1

    end

    return @sum

end

go

declare @n1 int

exec @n1 = qiuhe 5

print @n1

--------带返回值,返回参数,输入参数的存储过程--------

---输入学号，返回三门课的成绩

create proc sixproc

@yuwen decimal(18,2) output,

@shuxue decimal(18,2) output,

@yingyu decimal(18,2) output,

@code int

as

begin

    declare @count int  

    select @yuwen = yuwen,@shuxue = shuxue,@yingyu = yingyu from fenshu where code = @code

end

go

---定义变量接受存储过程带出来的输出参数的值

declare @yuwen decimal(18,2),@yingyu decimal(18,2),@shuxue decimal(18,2)

exec sixproc @yuwen output,@shuxue output, @yingyu output,1

print @yuwen+@yingyu+@shuxue

----------------------------------------------

alter proc sixproc

@yuwen decimal(18,2) output,

@shuxue decimal(18,2) output,

@yingyu decimal(18,2) output,

@code int

as

begin

    declare @count int

    select @count = COUNT(*)from student where code = @code

    select @yuwen = yuwen,@shuxue = shuxue,@yingyu = yingyu from fenshu where code = @code

    return @count

end

go

declare @yuwen decimal(18,2),@yingyu decimal(18,2),@shuxue decimal(18,2),@count int

exec @count = sixproc @yuwen output,@shuxue output, @yingyu output,15

print @yuwen+@yingyu+@shuxue

print @count

14、SQL基础整理（存储过程）