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HomeBackend DevelopmentPHP Tutorial 一段PHP的分页程序,报错,该如何解决

一段PHP的分页程序,报错
这是翻页程序:

PHP code
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include_once('conn.php');

if(isset($_GET['pclass']))
 {
   $p_class=$_GET['pclass'];
 }
else
 {
   $p_class='';
 }

$respage = mysql_query("SELECT COUNT(*) FROM product where p_class='$p_class';"); //$num 是数据表中符合条件的总纪录数
while($row = mysql_fetch_assoc($respage))
    {
      $num = $row[0];//这一行报错:Notice: Undefined offset: 0 in D:\setup\xampp\htdocs\products\showclass.php on line 88
    }
      $recordnum =40;   // 每页显示多少条记录, 
      $pages = ceil($num/$recordnum); //一共有多少页
    if (@$_GET["page"]) // 获取 url 中的参数 page
       {
      
     
     //$pre 和 $next 为后面前一页和后一页的连接参数 page 的值
     // 如果 url 中的参数为 1 ,把当前页置为 1 前一页, $pre 也为一, $next 为 2
       if($_GET["page"]==1)
         {
           $current = 1;//当前页
           $pre = 1;    //$pre 是前一页的
           $next = 2;   //$next 是后一页
          }
        else
          {
           $current = $_GET["page"];
           $pre = $current-1;
           $next = $current+1;
           }    // 如果 url 中的参数不为一(不是第一页),就把当前页取值为 url 中获得的参数, $pre 为当前页减 1 , $next 为加 1
        }
        else 
         {    
           $current = 1;
           $pre = '1';
           $next = 2;
          }// 如果 url 中没有参数 page ,当前页置为 1 , $pre=1,$next=2
        $now = ($current-1)*$recordnum;
        $echopage = "
"; $echopage .= ""; $echopage .= "";//报错:Notice: Undefined index: HP_SELF in D:\setup\xampp\htdocs\products\showclass.php on line 120 $echopage .= "";//报错:Notice: Undefined index: HP_SELF in D:\setup\xampp\htdocs\products\showclass.php on line 120 $echopage .= ""; $echopage .= "
".$pages." 页 第一页 最后一页 前一页 后一页 到第
";


下面是放在需要分页地方的代码:

PHP code
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<td><div id="page"><?php echo $echopage ?></div></td>



=====在WEB端报错:

Notice: Undefined offset: 0 in D:\setup\xampp\htdocs\products\showclass.php on line 88

Notice: Undefined index: HP_SELF in D:\setup\xampp\htdocs\products\showclass.php on line 120

Notice: Undefined index: HP_SELF in D:\setup\xampp\htdocs\products\showclass.php on line 120

Notice: Undefined index: HP_SELF in D:\setup\xampp\htdocs\products\showclass.php on line 121


------解决方案--------------------
$num = $row[0];//这一行报错
是因为 mysql_fetch_assoc 返回的是关联数组,没有下标
改为 mysql_fetch_array

HP_SELF 应为 PHP_SELF
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