在單個查詢中顯示2個計數結果

Question

我有一個訂單表，我想要顯示一個報告，顯示從單個表中拒絕的月份，總訂單和總訂單。

表有dtcomplete，rtpID和supplierReject，我想用，這幾乎讓我有，但應該只有1拒絕顯示爲1月，我想子查詢中只檢查分組月

select datename(month, dtComplete) as Month, count(rtpID) as TotalOrders, 
(select count(*) from RTPMaindetails where SupplierRejected = 1 and datename(month, dtComplete) = datename(month, RTPMaindetails.dtComplete) group by datepart(month,dtcomplete)) as Rejects 
from RTPMaindetails 
where datepart(year,dtComplete) = 2017 
group by datepart(month,dtcomplete),datename(month, dtComplete) 
order by datepart(month,dtcomplete) 

表演：

Month TotalOrders Rejects 
January 515    1 
February 308    1 
March  156    1 

應該顯示

Month TotalOrders Rejects 
January 515    1 
February 308    0 
March  156    0 

Answer 1

你可以做一個查詢

select 
    datename(month, dtComplete) as Month 
    , count(rtpID) as TotalOrders 
    , sum(case when SupplierRejected = 1 then 1 else 0) as Rejects 
from RTPMaindetails 
where datepart(year,dtComplete) = 2017 
group by datepart(month,dtcomplete) 
order by datepart(month,dtcomplete) 

Answer 2

這可能取決於你所使用的數據庫管理系統，但最應該支持這樣的事情：

select datename(month, dtComplete) as Month 
    , count(rtpID) as TotalOrders, 
    , count(case when SupplierRejected = 1 then rtpID end) as Rejects 
    from RTPMaindetails 
where datepart(year,dtComplete) = 2017 
group by datepart(month,dtcomplete),datename(month, dtComplete) 
order by datepart(month,dtcomplete)