Question

使用使用mysql代替mysqli/pdo的旧代码，所以不要担心这一点，我稍后会更新查询。

即使我当前的方法有效，但我很肯定有一种更简洁的方法，而不是查询和3个子查询。我主要想学习如何更好地增强我的查询并减少它们的数量我想做的是

echo显示每个日期的所有数据，日期显示在顶部
显示用户旁边某一天的每个用户的条目数

对于每个日期，在上述2位数据的底部，显示具有最多条目数的用户

$query = mysql_query('SELECT * FROM entries GROUP BY DATE(dt)');

$g = 0;

while ($row = @mysql_fetch_array($query)) 
{

    $group[$g] = date('y-m-d', strtotime($row['dt']));
    echo $group[$g] . "<br />";

    //display the person's name for today with their count
    $dayquery = mysql_query('SELECT *, COUNT(username) as total FROM entries WHERE DATE(dt) = "'.$group[$g].'" GROUP BY username ORDER BY COUNT(username) DESC');
        while ($today = @mysql_fetch_array($dayquery)) 
        {
            echo $today['first_name'] . " | " . $today['total'] . "<br />";
        }   

        //display the highest count for today
        $topquery = mysql_query('SELECT COUNT(username) as highest FROM entries WHERE DATE(dt) = "'.$group[$g].'" GROUP BY username ORDER BY COUNT(username) DESC LIMIT 1');
            while ($toptoday = @mysql_fetch_array($topquery)) 
            {
                echo "Highest today: " . $toptoday['highest'] . "<br /><br />" ;
            } 

            //display the users with the highest count for today
            echo "Highest users: ";
            $userstopquery = mysql_query('SELECT *, COUNT(username) as total FROM entries WHERE DATE(dt) = "'.$group[$g].'" AND COUNT(username) = "' . $toptoday['highest'] . '" AND GROUP BY username');
                while ($topusers = @mysql_fetch_array($userstopquery)) 
                {
                     echo $topusers['first_name'] . "<br />" ;
                } 

    $g++;

}

我遇到的麻烦是，当我尝试减少这些子查询并使用MAX时，它只输出最高计数但不输出每个日期的所有数据，这就是我需要的，包括输出具有该特定日期的最多条目的用户。

如何以更干净的方式执行这些MySQL子查询？

0 个答案: