PHP分页 - 在其他页面上显示正确内容的问题

Question

我在网上找到了这个很棒的代码来帮助分页，而且运行良好，唯一的问题是：每个页面显示相同的4行。

任何想法都将不胜感激

<?php
        //Include the PS_Pagination class
        include('includes/ps_pagination.php');

        //Connect to mysql db
        $conn = mysql_connect("localhost", "root", "root");
        mysql_select_db('database',$conn);
        $sql = "SELECT * FROM studies WHERE niche = '{$_GET['niche']}'";
        //Create a PS_Pagination object
        $pager = new PS_Pagination($conn,$sql,4,5);
        //The paginate() function returns a mysql
        //result set for the current page
        $rs = $pager->paginate();
        //Loop through the result set
        while($row = mysql_fetch_assoc($rs)) {

    $a=0;
    while ($a < $num) {

    $id=mysql_result($result,$a,"id");
    $title=mysql_result($result,$a,"title");
    $strategies=mysql_result($result,$a,"strategies");
    $client=mysql_result($result,$a,"client");
    $copy=mysql_result($result,$a,"copy");
    $thumbmedia=mysql_result($result,$a,"thumbmedia");
    $niche=mysql_result($result,$a,"niche");


    echo '<div class="container"><p class="subheadred"><a href="casestudy.php?id='.$id.'">'.$title.'</a></p></div>';

    echo '<div class="containerstudy"><div class="column1"><p class="subheadsmall">Strategies</p><p class="sidebarred">'.$strategies.'</p>';

    echo '<p class="subheadsmall">Client</p><p class="sidebargrey">'.$client.'</p></div>';

    echo '<div class="column2"><p class="bodygrey">'.substr($copy, 0, 300).'<a href="casestudy.php?id='.$id.'">...more</a></p></div>';

    echo '<div class="column3"><img src="images/'.$thumbmedia.'" height="160" /></div></div>';

    $a++;
    }

        }
        //Display the navigation
        echo $pager->renderNav();
    ?>

这是包含的文件：

<?php
/**
 * PHPSense Pagination Class
 *
 * PHP tutorials and scripts
 *
 * @package     PHPSense
 * @author      Jatinder Singh Thind
 * @copyright   Copyright (c) 2006, Jatinder Singh Thind
 * @link        http://www.phpsense.com
 */

// ------------------------------------------------------------------------

class PS_Pagination {
    var $php_self;
    var $rows_per_page; //Number of records to display per page
    var $total_rows; //Total number of rows returned by the query
    var $links_per_page; //Number of links to display per page
    var $sql;
    var $debug = false;
    var $conn;
    var $page;
    var $max_pages;
    var $offset;

    /**
     * Constructor
     *
     * @param resource $connection Mysql connection link
     * @param string $sql SQL query to paginate. Example : SELECT * FROM users
     * @param integer $rows_per_page Number of records to display per page. Defaults to 10
     * @param integer $links_per_page Number of links to display per page. Defaults to 5
     */

    function PS_Pagination($connection, $sql, $rows_per_page = 1, $links_per_page = 5) {
        $this->conn = $connection;
        $this->sql = $sql;
        $this->rows_per_page = $rows_per_page;
        $this->links_per_page = $links_per_page;
        $this->php_self = htmlspecialchars($_SERVER['PHP_SELF']);
        if(isset($_GET['page'])) {
            $this->page = intval($_GET['page']);
        }
    }

    /**
     * Executes the SQL query and initializes internal variables
     *
     * @access public
     * @return resource
     */
    function paginate() {
        if(!$this->conn) {
            if($this->debug) echo "MySQL connection missing<br />";
            return false;
        }

        $all_rs = @mysql_query($this->sql);
        if(!$all_rs) {
            if($this->debug) echo "SQL query failed. Check your query.<br />";
            return false;
        }
        $this->total_rows = mysql_num_rows($all_rs);
        @mysql_close($all_rs);

        $this->max_pages = ceil($this->total_rows/$this->rows_per_page);
        //Check the page value just in case someone is trying to input an aribitrary value
        if($this->page > $this->max_pages || $this->page <= 0) {
            $this->page = 1;
        }

        //Calculate Offset
        $this->offset = $this->rows_per_page * ($this->page-1);

        //Fetch the required result set
        $rs = @mysql_query($this->sql." LIMIT {$this->offset}, {$this->rows_per_page}");
        if(!$rs) {
            if($this->debug) echo "Pagination query failed. Check your query.<br />";
            return false;
        }
        return $rs;
    }

    /**
     * Display the link to the first page
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to 'First'
     * @return string
     */
    function renderFirst($tag='First') {
        if($this->page == 1) {
            return $tag;
        }
        else {
            return '<a href="'.$this->php_self.'?page=1">'.$tag.'</a>';
        }
    }

    /**
     * Display the link to the last page
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to 'Last'
     * @return string
     */
    function renderLast($tag='Last') {
        if($this->page == $this->max_pages) {
            return $tag;
        }
        else {
            return '<a href="'.$this->php_self.'?page='.$this->max_pages.'">'.$tag.'</a>';
        }
    }

    /**
     * Display the next link
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to '>>'
     * @return string
     */
    function renderNext($tag=' &gt;&gt;') {
        if($this->page < $this->max_pages) {
            return '<a href="'.$this->php_self.'?page='.($this->page+1).'">'.$tag.'</a>';
        }
        else {
            return $tag;
        }
    }

    /**
     * Display the previous link
     *
     * @access public
     * @param string $tag Text string to be displayed as the link. Defaults to '<<'
     * @return string
     */
    function renderPrev($tag='&lt;&lt;') {
        if($this->page > 1) {
            return '<a href="'.$this->php_self.'?page='.($this->page-1).'">'.$tag.'</a>';
        }
        else {
            return $tag;
        }
    }

    /**
     * Display the page links
     *
     * @access public
     * @return string
     */




    function renderNav() {
        for($i=1;$i<=$this->max_pages;$i+=$this->links_per_page) {
            if($this->page >= $i) {
                $start = $i;
            }
        }

        if($this->max_pages > $this->links_per_page) {
            $end = $start+$this->links_per_page;
            if($end > $this->max_pages) $end = $this->max_pages+1;
        }
        else {
            $end = $this->max_pages;
        }

        $links = '';
        $niche = $_GET['niche'];

        for( $i=$start ; $i<$end ; $i++) {
            if($i == $this->page) {
                $links .= " $i ";
            }
            else {
                $links .= ' <a href="'.$this->php_self.'?page='.$i.'&niche='.$niche.'">'.$i.'</a> ';
            }
        }

        return $links;
    }

    /**
     * Display full pagination navigation
     *
     * @access public
     * @return string
     */
    function renderFullNav() {
        return $this->renderFirst().'&nbsp;'.$this->renderPrev().'&nbsp;'.$this->renderNav().'&nbsp;'.$this->renderNext().'&nbsp;'.$this->renderLast(); 
    }

    /**
     * Set debug mode
     *
     * @access public
     * @param bool $debug Set to TRUE to enable debug messages
     * @return void
     */
    function setDebug($debug) {
        $this->debug = $debug;
    }
}
?>

Answer 1

乍一看，我发现你的查询每次运行时都会从头开始重复，这意味着每次运行它都会从开始搜索。你需要一个计数器告诉它从下一页开始。类似的东西：

$sql = "SELECT * FROM studies WHERE niche = '{$_GET['niche']}' limit $startPoint, $offset";

这样，偏移量与每页所需的项目数相同，而$ startPoint是下次迭代时搜索开始的点。

这样的事情会起作用：

if(!$startPoint){$startPoint = 0;}else{$startPoint = {$_GET['$startPoint'];}

代码中的

将起点传递回查询，并在每次迭代后通过偏移量增加它。

请记住，我没有考虑注入之类的东西，以及变量$ num似乎不是来自第一个文件中的任何地方。我无法看到你在哪里初始化它以便测试$ a。

在更深入地查看您的代码之后，我发现需要更改一些内容以使其工作至少在这里是更改的代码：

<?php
        //Include the PS_Pagination class
       include('includes/ps_pagination.php');

        //Connect to mysql db
        $conn = mysql_connect("localhost", "root", "root");
        mysql_select_db('database',$conn);
        $sql = "SELECT * FROM studies";// WHERE niche = '{$_GET['niche']}'";
        //Create a PS_Pagination object
        $pager = new PS_Pagination($conn,$sql,4,5);
        //The paginate() function returns a mysql
        //result set for the current page
        $rs = $pager->paginate();
        //Loop through the result set
        while($row = mysql_fetch_assoc($rs)) {

 //   $a=0;
 //   while ($a < $num) {

 //   $id=mysql_result($result,$a,"id");
 //   $title=mysql_result($result,$a,"title");
  //  $strategies=mysql_result($result,$a,"strategies");
 //   $client=mysql_result($result,$a,"client");
 //   $copy=mysql_result($result,$a,"copy");
 //   $thumbmedia=mysql_result($result,$a,"thumbmedia");
 //   $niche=mysql_result($result,$a,"niche");
    $id=$row['id'];
    $title=$row['title'];
    $strategies=$row['strategies'];
    $client=$row['client'];
    $copy=$row['copy'];
    $thumbmedia=$row['thumbmedia'];
    $niche=$row['niche'];

    echo '<div class="container"><p class="subheadred"><a href="casestudy.php?id='.$id.'">'.$title.'</a></p></div>';

    echo '<div class="containerstudy"><div class="column1"><p class="subheadsmall">Strategies</p><p class="sidebarred">'.$strategies.'</p>';

    echo '<p class="subheadsmall">Client</p><p class="sidebargrey">'.$client.'</p></div>';

    echo '<div class="column2"><p class="bodygrey">'.substr($copy, 0, 300).'<a href="casestudy.php?id='.$id.'">...more</a></p></div>';

    echo '<div class="column3"><img src="images/'.$thumbmedia.'" height="160" /></div></div>';

  //  $a++;
  //  }

        }
        //Display the navigation
        echo $pager->renderNav();
    ?>

注意我已经注释了一些不必要的部分

变量$ a没有意义，因为它与$ num相比，因为它不存在，因此没有任何东西可以显示。现在这些行：

   //   $id=mysql_result($result,$a,"id");
     //   $title=mysql_result($result,$a,"title");
      //  $strategies=mysql_result($result,$a,"strategies");
     //   $client=mysql_result($result,$a,"client");
     //   $copy=mysql_result($result,$a,"copy");
     //   $thumbmedia=mysql_result($result,$a,"thumbmedia");
     //   $niche=mysql_result($result,$a,"niche");

当您尝试从$ result获取结果集时，也会出错。在任何地方你都没有将结果集放入$ result中，你导入的类就是这样做，并将结果集放入一个名为$ rs的标识符中。

由于您使用$row = mysql_fetch_assoc($rs)来读取结果集，然后获取变量，您需要做的就是通过这样的数组获取列行

$id=$row['id'];

等等。一旦你这样做，那么代码应该按预期工作。然而，这让我们回到了这一点：

$sql = "SELECT * FROM studies WHERE niche = '{$_GET['niche']}'";

我必须得到最后一部分，因为这个变量没有被传递回查询字符串（看到你正在使用get），另一个问题是你第一次加载页面时这个变量'niche'没有' t存在所以第一次运行代码时，您将得到一个空白页，除非通过传入此变量的链接访问此脚本。在这一点上，我已经离开它注释掉，因为我不确定你想通过利基做什么。

希望有所帮助。

Answer 2

您的查询字符串中是否设置了页面？

Answer 3

我不确定这个分页库对行的索引做了什么，但是你总是将$ a设置为0.也许索引不是相对于页面而是返回给整个记录集？

换句话说，如果你在第1页将$ a设置为0，在第2页设置4，等等。

您应该可以使用$ rows_per_page和$ page来计算它。或者这可能是$ offset值，因此您将$ a设置为offset并循环它直到您点击$ rows_per_page其他行。

---

修改澄清解决方案：
所以我看到你能做的是：

$a=0;
while ($a < $pager->rows_per_page) {
    $row = $a + $pager->offset;

    $id=mysql_result($result,$row,"id");
    $title=mysql_result($result,$row,"title");
    $strategies=mysql_result($result,$row,"strategies");
    $client=mysql_result($result,$row,"client");
    $copy=mysql_result($result,$row,"copy");
    $thumbmedia=mysql_result($result,$row,"thumbmedia");
    $niche=mysql_result($result,$row,"niche");

    ...
    $a++;
}

Answer 4

我认为如果您更改了paginate函数，那么它将有一个参数$page，并且您将在函数的开头设置$this->page = $page，它将起作用。

您还必须将代码中此函数的调用更改为$pager->paginate($_GET['page'])。

寻呼机的效率也很低，它只是为了找出整个查询，响应有多少行。我会使用类似的东西：

$all_rs = @mysql_query('SELECT COUNT(*) FROM (' . $this->sql . ')');
if(!$all_rs) {
        if($this->debug) echo "SQL query failed. Check your query.<br />";
        return false;
}
$this->total_rows = mysql_result($all_rs, 0, 0);
@mysql_close($all_rs);