动态分组查询

最新推荐文章于 2023-11-14 16:43:57 发布

最新推荐文章于 2023-11-14 16:43:57 发布 · 367 阅读

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#Go #.net #XML

博客给出了一个SQL示例，创建了表并插入数据，实现按输入分组参数（如“3,6”“2,5,8”）进行分组查询。通过创建存储过程p_qry处理分组逻辑，最后调用存储过程查询并删除测试表和存储过程，展示了查询结果。

原帖地址:
http://community.youkuaiyun.com/Expert/topic/3428/3428792.xml?temp=.6476251

--示例数据
create table 表(ID int,NUM int)
insert 表 select 1,2
union all select 2,3
union all select 3,2
union all select 4,2
union all select 5,12
union all select 6,2
union all select 7,1
union all select 8,5
union all select 9,1
go

/*--问题说明:

输入分组参数,比如输入 "3,6" ,实现按 ID<=3,3<ID<=6,ID>6 分组查询
输入分组参数,比如输入 "2,5,8" ,实现按 ID<=2,2<ID<=5,5<ID<=8,ID>8 分组查询
--*/

--查询的存储过程
create proc p_qry
@numlist varchar(1000)
as
set nocount on
declare @t table(id int identity,组 varchar(10),a int,b int)
declare @i int,@pnum varchar(10)
select @i=charindex(',',@numlist+',')
,@pnum=left(@numlist,@i-1)
,@numlist=stuff(@numlist,1,@i,'')
,@i=charindex(',',@numlist)
insert @t select 'id<='+@pnum,null,@pnum
while @i>0
begin
insert @t select @pnum+'<id<='+left(@numlist,@i-1),@pnum,left(@numlist,@i-1)
select @pnum=left(@numlist,@i-1)
,@numlist=stuff(@numlist,1,@i,'')
,@i=charindex(',',@numlist)
end
insert @t select 'id>'+@numlist,@numlist,null

select b.组,num=sum(a.num)
from 表 a,@t b
where case
when b.a is null then case when a.id<=b.b then 1 else 0 end
when b.b is null then case when a.id>b.a then 1 else 0 end
else case when a.id>b.a and a.id<=b.b then 1 else 0 end
end=1
group by b.组
order by min(b.id)
go

--调用存储过程进行查询
exec p_qry '2,5,8'
go

--删除测试
drop table 表
drop proc p_qry

/*--测试结果

组 num
---------- -----------
id<=2 5
2<id<=5 16
id>8 1
--*/