Question

所以我有这个样本表。包含所有互联网商店分支机构OS的安装数据。

ID   ShopName   PCName   OS
1    Mineski    M101     WinXP
2    Mineski    M102     WinXP
3    GameCity   G201     Win7
4    GameCity   G202     Win7
5    CyberBob   C301     WinXP
6    CyberBob   C302     Win7

我需要查询Shop安装的OS。

我可以使用此查询执行此操作。

select ShopName, OS
from ShopInv
group by ShopName, OS

预期结果将是：

ShopName    OS
CyberBob    Win7
CyberBob    WinXP
GameCity    Win7
Mineski     WinXP

但是，我只希望列出每个商店1行。因此，如果有超过1行（由于安装了不同的OS版本），就像上面的示例一样。我只是想显示混合。

所以结果会是这样的：

ShopName    OS
CyberBob    Mixed
GameCity    Win7
Mineski     WinXP

这在SQL Server 2008上是否可行？

SQLFiddle

注意：我对如何陈述我的问题有点困惑，所以如果你愿意，请编辑它。：）

Answer 1

对于每次case检查，您可以使用distinct OS count值ShopName：

select ShopName
     , case when count(distinct OS) > 1 then 'Mixed' else min(OS) end
from ShopInv
group by ShopName

SQLFiddle

Answer 2

这很简单：因为您希望每个商店有一排，所以只能按店铺分组。然后使用聚合函数获取操作系统。这可以是MIN或MAX。但是，如果您检测到，那么MIN＆lt;＆gt; MAX，然后你必须显示＆＃39;混合＆＃39;代替。

select 
  ShopName,
  case when MIN(OS) = MAX(OS) then MIN(OS) else 'Mixed' end as OS
from ShopInv
group by ShopName;

Answer 3

如前所述，我已经给出了预期的输出

 declare @t table (Id int,Shop varchar(10),PCname varchar(10),OS Varchar(10))

    insert into @t (Id,Shop,PCname,os)values (1,'Mineski','M101','WinXP'),
    (2,'Mineski','M102','WinXP'),(3,'GameCity','G201','Win7'),
    (4,'GameCity','G202','Win7'),(5,'CyberBob','C301','WinXP'),
    (6,'CyberBob','C302','Win7')

第一个结果

;with cte as (
select shop,OS,ROW_NUMBER()OVER(PARTITION BY shop,OS ORDER BY shop ) rn from @t)
select shop,OS from cte
where rn = 1

最终结果集

;with cte as (
select shop,OS,ROW_NUMBER()OVER(PARTITION BY shop,OS ORDER BY shop ) rn from @t)
,CTE2 AS (
Select shop,CASE WHEN R = 1 THEN 'MIXED' ELSE OS END AS 'OS' from (
select shop,OS,count(rn)R from cte
group by Shop,OS )S )
select DISTINCT shop,OS from CTE2

Answer 4

select Shopname,
(select case when count(shopname)>1 then 'Mixed' 
         else OS 
         from ShopInv b
         where a.shopname=b.shopname
         group by b.shopname)
from ShopInv a

如何将两个值（行）组合成一个具有自定义值的行？

4 个答案: