我想顯示一個表中的記錄

Question

SELECT vhfloorno, 
     Count(ischeckin) AS ChecKIn, 
     Count(ischeckout) AS CheckOut 
FROM visitorhistory t1 
WHERE (Year(vhcheckinebi) = Year(@From) 
     AND Month(vhcheckinebi) = Month(@From) 
     AND Day(vhcheckinebi) = Day(@From)) 
     OR (Year(vhcheckoutebi) = Year(@To) 
      AND Month(vhcheckoutebi) = Month(@To) 
      AND Day(vhcheckoutebi) = Day(@To)) 
GROUP BY vhfloorno 

我想根據樓層顯示從一個表格中檢入和檢出訪客的數量，但通過此查詢，檢入和檢出值相同。 其中vhcheckinebi是訪客入住時的日期時間，而vhcheckoutebi是訪客入住時的日期時間。 請幫幫我。

Answer 1

也許你想有條件聚集：

SELECT vhfloorno, 
     sum(case when ischeckin = 1 then 1 else 0 end) AS ChecKIn, 
     sum(case when ischeckout = 1 then 1 else 0 end) AS CheckOut 
FROM visitorhistory t1 
... 

Answer 2

假設你的列ischeckin類型爲bit你應該 使用SUM(CAST(ischeckin as INT))代替Count(ischeckin)否則兩個「假」與「真」值將每次計數：

SELECT vhfloorno, 
     SUM(CAST(ischeckin as INT)) AS ChecKIn, 
     SUM(CAST(ischeckout as INT)) AS CheckOut 
FROM visitorhistory t1 
WHERE ... 

看到這裏最少例如：http://data.stackexchange.com/stackoverflow/query/477199/checkin-and-checkout-counts