結合2個複雜的MySQL查詢到一個

當前 - 表

ID - Unique identifier for device (Int) 
Location -Unique identifier for name of area (VarChar) 
Status - The current status of the device (VarChar) 
Time - DateTime of when the last connection was made to the device (DateTime)

歷史 - 表

CID (Sorta unused, just as an AI field to store multiple old bits of data uniquely) (Int) 
ID - Unique identifier for device (Int) 
Location --Unique identifier for name of area (VarChar) 
Status - The current status of the device (VarChar) 
Time -- DateTime of when the last connection was made to the device (DateTime)

所以這是數據庫如何看起來現在我的查詢看起來像這樣......

查詢1

SELECT c.*, 
    if(HOUR(TIMEDIFF(NOW(), c.TIME)) >=1, 1, 0) as LatestOlderThanAnHour, 
    min(h.time) as EarliestTime, 
    (abs(timestampdiff(HOUR,NOW(),min(TIME)))/count(*)*100) as percentage 
FROM Current c 
JOIN Historical h on c.ID = h.ID 
WHERE c.Location like "MyLocation" 
group by c.ID

查詢2

SELECT MAX(h.TIME) AS LastDown 
FROM TABLENAME 
WHERE h.STATUS IN ('On-Login-Screen','IE-Window-Missing')

的最終目標是添加一個「最後向下」列由該查詢返回的每一ID。我只是無法弄清楚如何去做。

來源

2013-05-07 A_Elric

'MAX（情況下h.status在（ '在登錄屏幕'， 'IE-窗口 - 缺少'），然後小時。時間結束）' – 2013-05-07 20:20:59

^^將其作爲答案，以便我可以接受它，並非常感謝你！ – 2013-05-07 20:34:07

max(case when h.status in ('On-Login-Screen','IE-Window-Missing') then h.time end)

或者我猜你也可以把它寫

max(if(h.status in ('On-Login-Screen','IE-Window-Missing'), h.time, NULL))

來源

2013-05-07 20:36:49

結合2個複雜的MySQL查詢到一個

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