PHP MySQL缺少行（bug？）

从应答中添加另外两个连接将使查询不返回任何内容

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必须先运行子选择联接，然后再运行其他两个表的联接。然后，在与其他表的两个联接中，必须显式引用所需的表。所以在我的例子中，主选择是“tblname1 v”，然后次选择是“r”。然后您引用v.ID=othertbl.ID

请尝试与

左连接建立关系

：

LEFT JOIN 
(SELECT tblreview.AssistantIdentNumber,
tblreview.AssistId,
tblreview.Status, 
tblreview.ManagerId AS RevID, 
tblreviewer.Forename AS RevForename, 
tblreviewer.Surname AS RevSurname 
FROM tblreview, tblreviewer 
WHERE tblreview.ReviewerId = tblreviewer.ReviewerId 
AND tblreview.Status = 'Complete' 
AND IsNull(tblreview.Validation)) r

选择
tblreview.assistantItemNumber，
tblreview.AssistID，
tblreview.状态，
tblreview.ReviewerId为RevID，
tblAssistant.Forename作为RevForename，
t lassistant.姓为revlasname，
tblreview.验证
来自tblreview
左连接tblreviewer
在tblreview.ReviewerID=tblreviewer.ReviewerID上
左连接tblAssistant
在tblAssistant.IdentNumber=tblreview.AssistantIdentNumber上
哪里
tblreview.Validation='Y'
和t lassistant。测试“Y”
年份（STR_TO_DATE（tblAssistant.DateDied，'%d/%m/%Y'））='2014'
月份（STR_TO_DATE（tblAssistant.DateDied，'%d/%m/%Y'））='9'；

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使用

左连接

而不是

WHERE

。谢谢。工作完美。你能解释一下为什么它需要这个吗？请阅读这篇文章了解“where和join关系之间的区别”：谢谢。你能解释一下第三个连接是如何与其他所有连接集成的吗？

SELECT 
  tblreview.AssistantIdentNumber, 
  tblreview.AssistID,
  tblreview.Status,
  tblreview.ReviewerId AS RevID,
  tblAssistant.Forename AS RevForename,
  tblAssistant.Surname AS RevSurname,
  tblreview.Validation 
FROM tblreview, tblreviewer, tblAssistant
WHERE
  tblreview.ReviewerID = tblreviewer.ReviewerID
  AND tblreview.Validation = 'Y'
  AND tblAssistant.Test <> 'Y'
  AND tblAssistant.IdentNumber = tblreview.AssistantIdentNumber
  AND YEAR(STR_TO_DATE(tblAssistant.DateDied,'%d/%m/%Y')) = '2014'
  AND MONTH(STR_TO_DATE(tblAssistant.DateDied,'%d/%m/%Y')) = '9';

for($i=0;$i<$rowCount;$i++) 
{
    $row[$i]= mysql_fetch_array($ValidationPart);
    // writes out HTML table
}

for($i=0;$i<$rowCount;$i++) 
{
    $row[$i]= mysql_fetch_array($ValidationPart);
    if (empty($row[$i]['IdentNumber']))
    { 
        //do nothing
    } else {
        // Prints out HTML table
    }
}

LEFT JOIN 
(SELECT tblreview.AssistantIdentNumber,
tblreview.AssistId,
tblreview.Status, 
tblreview.ManagerId AS RevID, 
tblreviewer.Forename AS RevForename, 
tblreviewer.Surname AS RevSurname 
FROM tblreview, tblreviewer 
WHERE tblreview.ReviewerId = tblreviewer.ReviewerId 
AND tblreview.Status = 'Complete' 
AND IsNull(tblreview.Validation)) r

SELECT 
  tblreview.AssistantIdentNumber, 
  tblreview.AssistID, 
  tblreview.Status, 
  tblreview.ReviewerId AS RevID, 
  tblAssistant.Forename AS RevForename, 
  tblAssistant.Surname AS RevSurname, 
  tblreview.Validation 
FROM tblreview
LEFT JOIN tblreviewer
  ON tblreview.ReviewerID = tblreviewer.ReviewerID
LEFT JOIN tblAssistant 
  ON tblAssistant.IdentNumber = tblreview.AssistantIdentNumber 
WHERE 
  tblreview.Validation = 'Y'
  AND tblAssistant.Test <> 'Y' 
  AND YEAR(STR_TO_DATE(tblAssistant.DateDied,'%d/%m/%Y')) = '2014' 
  AND MONTH(STR_TO_DATE(tblAssistant.DateDied,'%d/%m/%Y')) = '9';