Question

在我的事件表中，我有一个名为Pos1的列，其中包含从A到E的ID。我需要计算“E”在列中出现的次数以及它与其他数字并排的位置。

例如，在此表中，“E”出现 1 时间，排名 4 （D = 3，A = 2，C = 2，E = 1，B = 0）。

Pos1
E
C
D
C
D
D
A
A

我是一个完整的SQL业余爱好者，所以我最接近的是打印每个ID计数的数组，但我需要将其限制为计算单个ID 和打印排名

$query = "SELECT Pos1, COUNT(Pos1) FROM Events GROUP BY Pos1"; 

$result = mysql_query($query) or die(mysql_error());

while($row = mysql_fetch_array($result)){

    echo $row['COUNT(Pos1)'] ."<br />";

}

Answer 1

试试这个：

SELECT Pos1, a.cnt, rank
FROM(
    SELECT a.Pos1, a.cnt, (@rank := @rank + 1) AS rank
    FROM(
        SELECT Pos1, COUNT(Pos1) cnt
        FROM Events
        GROUP BY Pos1
    ) a, (SELECT @rank := 0) b
    ORDER BY a.cnt DESC
)a
WHERE a.pos1 = 'E';

SQLFIDDLE DEMO HERE

编辑：php代码

$query = "SELECT Pos1, a.cnt, rank
          FROM(
            SELECT a.Pos1, a.cnt, (@rank := @rank + 1) AS rank
            FROM(
                SELECT Pos1, COUNT(Pos1) cnt
                FROM Events
                GROUP BY Pos1
            ) a, (SELECT @rank := 0) b
            ORDER BY a.cnt DESC
          )a
          WHERE a.pos1 = '$pos1'";

$result = mysql_query($query) or die(mysql_error());

$row = mysql_fetch_row($result);

echo $row['Pos1']." ".$row['cnt']." ".$row['rank']."<br />";

Answer 2

或者在PHP中排名：

$query = "SELECT Pos1, COUNT(Pos1) AS qty FROM Events GROUP BY Pos1 ORDER BY qty DESC"; 

$result = mysql_query($query) or die(mysql_error());
$rank=1;
while($row = mysql_fetch_array($result))
{
    echo $rank.": ".$row['Pos1']."(".$row['qty'].")<br />";
    $rank++;
}

计算表中的出现次数并打印计数和排名

2 个答案: