php - 查找上周投票最高的问题。 (sql查询)

Question

我有3个sql表:

qotwQuestion1a(QuestionId [primarykey], Question, MemberId, PostDate);
qotwVote1a (QuestionId [primarykey], MemberId [primarykey], Vote1a);
qotwMember (MemberId [primarykey], Name, Password, emailId);

我想编写一个sql查询来查找上周投票最高的问题的QuetionId和MemberId。我已经用 php 编写了这个查询，但它给出了错误的结果:

$result6 = mysql_query("SELECT MAX(Vote1a) AS highestVote, * FROM qotwMember, qotwQuestion1a , qotwVote1a
                    WHERE   qotwMember.MemberId=qotwQuestion1a.MemberId 
                    AND     qotwQuestion1a.QuestionId=qotwVote1a.QuestionId 
                    AND     qotwQuestion1a.MemberId=qotwVote1a.MemberId
                    AND     PostDate>='".$startofweek."' AND PostDate<='".$endofweek."'
                    ORDER BY qotwQuestion1a.QuestionId DESC ");
while($row6 = mysql_fetch_array($result6))
  {
  echo "The highest voted question of the last week is: "; echo $row6['highestVote']; echo $row6['MemberId'] . " " . $row6['Name'] . " " . $row6['Password'] . " " . $row6['PostDate'] . " " . $row6['Question']." ".$row6['QuestionId']." ".$row6['Vote1a'];
  echo "<br />";
  }

$startofweek 和 $endofweek 给出上周开始和上周结束的日期。

有人可以帮我解决这个问题吗？

最佳 泽尚

Answer 1

SELECT  *
FROM    (
        SELECT  q.QuestionId, q.MemberID
        FROM    qotwQuestion1a q
        JOIN    qotwVote1a v
        ON      v.QuestionID = q.QuestionID
        WHERE   PostDate BETWEEN $startdate AND $enddate
        GROUP BY
                q.questionID
        ORDER BY
                COUNT(*) DESC
        LIMIT 1
        ) qo
JOIN    qotwMember m
ON      m.MemberID = q.MemberID