MySQL查詢返回空結果集

Question

您好我有以下兩個表：

設備表：

deviceID accountID InstallTime fName   lName 
1   2   NULL   Dave   O'Riordan 
2   2   NULL   Kathrine  Hutter 
3   2   NULL   Guy   Swider 

a2_deal表：

deviceID companyID contactID stage event state serverTime clientTime monetary 
1   1   1  -1  CALL OUT  1349445600 1349445600 4600 
1   14   12  -1  CALL OUT  1349449200 1349449200 5400 
2   16   19  -1  CALL OUT  1349445600 1349445600 4456 
2   21   20  -1  CALL OUT  1349449200 1349449200 4000 
3   17   22  -1  CALL OUT  1349447160 1349447160 12000 
1   1   1   1  CALL OUT  1349082060 1349082060 NULL 
1   14   12   1  CHECK IN  1349083380 1349083380 NULL 
1   1   1   1  CHECK IN  1349082660 1349082660 NULL 
1   14   12   1  CHECK OUT  1349085382 1349085382 NULL 
1   1   1   1  CHECK OUT  1349082700 1349082700 NULL 

我做了一個查詢作爲如下：

SELECT deal.deviceID, devices.fName, devices.lName, SUM(event) AS visits 
FROM `a2_deal` AS deal 
LEFT JOIN `devices` AS devices ON deal.deviceID = devices.deviceID 
WHERE `event` LIKE 'CHECK' 
AND `serverTime` >= 1349082060 
AND `serverTime` <= 1349190000 
GROUP BY deal.deviceID 
ORDER BY visits 

它工作得很好，給我造成.... 但是當我試圖以檢索從列階段在a2_deal表基於條件的給我任何結果（結果爲空）的數據...

SELECT deal.deviceID, devices.fName, devices.lName, SUM(stage) AS closes 
FROM `a2_deal` AS deal 
LEFT JOIN `devices` AS devices ON deal.deviceID = devices.deviceID 
WHERE `stage` = -1 
AND `serverTime` >= 1349082060 
AND `serverTime` <= 1349190000 
GROUP BY deal.deviceID 
ORDER BY closes 

任何建議，我在做什麼錯了...謝謝你

Answer 1

查詢與

WHERE `stage` = -1 
AND `serverTime` >= 1349082060 
AND `serverTime` <= 1349190000 

沒有再打開任何結果，因爲stage = -1的所有值都超出了定義的範圍。

在旁註中，您可以使用serverTime BETWEEN <start> AND <end>。