我想編寫一個彙總查詢並將結果呈現在一個表中

Question

我需要針對3種不同的狀態值編寫彙總報告，每種狀態都有一個計數和一個金額列，結果顯示在一張表中。例如，輸出應該是這樣的：

以產生每行代碼（在一個單獨的輸出）該查詢是：

select case when status_key = '2' then 'Paid' else '' end as 'Status' 
, COUNT(BillNo) as [Count] 
, SUM(amtpd) as [Amount Paid] 
from billtable 
where client = 101 
and status_key = '2' 
group by status_key 

select case when status_key = '1' then 'Queued' else '' end as 'Status' 
, COUNT(BillNo) as [Count] 
, SUM(amtpd) as [Amount Paid] 
from billtable 
where client = 101 
and status_key = '1' 
group by status_key 

select case when status_key = '4' then 'Hold' else '' end as 'Status' 
, COUNT(BillNo) as [Count] 
, SUM(amtpd) as [Amount Paid] 
from billtable 
where client = 101 
and status_key = '4' 
group by status_key 

這產生三個結果一樣：

我使用SQL Server數據庫和SSMS發展查詢。

Answer 1

不需要聯合。

使用WHERE只篩選所需的status_keys，然後展開CASE語句以從數字重新編碼爲單詞。

select 
    case when status_key = '2' then 'Paid' 
     when status_key = '1' then 'Queued' 
     when status_key = '4' then 'Hold' 
          else 'Error!' end  AS [Status], 
    COUNT(BillNo)         AS [Count], 
    SUM(amtpd)          AS [Amount Paid] 
from 
    billtable 
where 
    client = 101 
    AND status_key IN ('1','2','4') 
group by 
    status_key 

編輯使用維度表

select 
    status.description         AS [Status], 
    COUNT(bill_table.BillNo)        AS [Count], 
    SUM(bill_table.amtpd)         AS [Amount Paid] 
from 
    billtable 
inner join 
    status 
    on billtable.status_key = status.key 
where 
     bill_table.client  = 101 
    AND bill_table.status_key IN ('1','2','4') 
group by 
    status.description 

然後你可以有一個外鍵約束從status到billtable變形例。這將確保數據不能插入billtable，除非status中有對應的密鑰。

您的查找將始終有效。但是如果status表未被正確填充，插入失敗的代價是「失敗」。

這fact-table和dimension-table構建是關係數據庫設計的基礎。

Answer 2

你就必須聯合所有

your first query 
Union all 
your Second query 
union all 
your third query 

Answer 3

只需將您的查詢之間添加UNION。