[請益] 拜託指點一SQL查詢order by 的問題

[s900527 (水)]

$sql = "select r.id,m.name,count(*),SUM(r.amnt) as ammount FROM member as m , rent as r WHERE r.id = '".$id."' and r.id = m.id group by id order by ammount DESC";
  // select c.bookid,c.title,count(*),sum(r.amnt) as ammount from rent as r
  // here  and r.bookid=c.bookid and r.id=m.id group by c.bookid order by ammount desc";
   $a = mysql_query($sql);
   while(list($aid,$name,$count,$sum)=mysql_fetch_row($a))
    {
    echo "<tr>";
    echo "<td>$aid</td>";
    echo "<td>$name</td>";
    echo "<td>$count</td>";
    echo "<td>$sum</td>";
    echo "</tr>";
    $total += $sum;
    }
  }

這是我的程式碼想讓他最後按照$sum的大小遞減排序
可是卻沒辦法
不知道是哪邊出了錯誤
拜託各位大大指點一下
感激不盡

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推 thitbbeb:order by 後面改成SUM(r.amnt)試試= =
推 s900527:我有試過改那樣不過他會顯示查詢語法錯誤說@@
推 thitbbeb:我想問你count(*)要做啥用的= =?會不會是它的關係~刪掉試
→ thitbbeb:還有你這是二個資料表關聯嗎?m.id=r.id?為啥不用join?
推 s900527:count是因為要計算他的次數~@@我要判斷他每本書的出現次數
→ s900527:兩個資料表示關聯查詢的@@join是什麼阿我不會耶= =
推 wa120:mysql之前用過"欄位"不能跟count()放在一起