Iss具有不同的值

Question

我在這裏有一些php代碼，它應該顯示來自一個名爲'Collections'的字段的unique/disctinct值。我已成功連接到其他地方的數據庫。當此PHP代碼執行，瀏覽器給了我一個「警告：mysql_fetch_array（）：提供的參數不是在mypage.php一個有效的MySQL結果資源在第20行」

  $id = isset($_GET['id'])?(int)$_GET['id']:0; // if $_GET['id'] exists, return it as an integer, otherwise use a sentinel, id's usually start with 1, so 0 works 

     if ($id!=0): 
// I assume this is a specific news item meaning you know it's ONE result 
$query = 'SELECT * DISTINCT (Collections) FROM Audios LIMIT 40'; // so try to use limit  1, no need to add extra steps in the database lookup 
    else: 
$query = 'SELECT * DISTINCT (Collections) FROM Audios ORDER BY Collections DESC LIMIT 40'; 
    endif; 

    $result = mysql_query($query); 
; 
// now loop through the results ***(This is Line 20)*** 
while ($row = mysql_fetch_array($result)){ 
// and use'em however you wish 
echo ' 

<div> 

    <li><a href="#">'.$row['Collections'].'</a></p> 
</div> 
'; 
    } 

Answer 1

SELECT DISTINCT (Collections) FROM Audios ORDER BY Collections DESC LIMIT 40 

兩個取出*查詢。