分页显示是浏览大量数据的一种方法。对于初学者来说常常对这个问题摸不着头绪,因此特地撰写此文对这个问题进行详细的讲解,力求让看完这篇文章的朋友在看完以后对于分页显示的原理和实现方法有所了解。
所有示例代码均使用php编写。
所谓分页显示,也就是将数据库中的结果集人为的分成一段一段的来显示。
请详细阅读以下代码,自己调试运行一次,最好把它修改一次,加上自己的功能。
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$wherelist = array ();
$urlist = array ();
if (! empty ( $_GET [ 'title' ]))
{
$wherelist []= " title like '%" . $_GET ['title ']."%' ";
$urllist []= "title=" . $_GET [ 'title' ];
}
if (! empty ( $_GET [ 'keywords' ]))
{
$wherelist []= " keywords like '%" . $_GET ['keywords ']."%' ";
$urllist []= "keywords=" . $_GET [ 'keywords' ];
} if (! empty ( $_GET [ 'author' ]))
{
$wherelist []= " author like '%" . $_GET ['author ']."%' ";
$urllist []= "author=" . $_GET [ 'author' ];
}
$where = "" ;
if ( count ( $wherelist )>0)
{
$where = " where " .implode( ' and ' , $wherelist );
$url = '&' .implode( '&' , $urllist );
}
//分页的实现原理
//1.获取数据表中总记录数
$sql = "select count(*) from news $where " ;
$result =mysql_query( $sql );
$totalnum =mysql_num_rows( $result );
//每页显示条数
$pagesize =5;
//总共有几页
$maxpage = ceil ( $totalnum / $pagesize );
$page =isset( $_GET [ 'page' ])? $_GET [ 'page' ]:1;
if ( $page <1)
{
$page =1;
}
if ( $page > $maxpage )
{
$page = $maxpage ;
}
$limit = " limit " .( $page -1)* $pagesize . ",$pagesize" ;
$sql1 = "select * from news {$where} {$limit}" ;
//$sql1="select * from news {$where} {$limit}";
$res =mysql_query( $sql1 );
?>
<form action= "searchpage.php" method= "get" >
标题:<input type= "text" name= "title" value= "<?php echo $_GET['title']?>" size= "8" >
关键字<input type= "text" name= "keywords" value= "<?php echo $_GET['keywords']?>" size= "8" >
作者:<input type= "text" name= "author" value= "<?php echo $_GET['author']?>" size= "8" >
<input type= "button" value= "查看全部" onclick= "window.location='searchpage.php'" >
</form>
<table border= "1" width= "1000" align= "center" >
<tr>
<td>编号</td>
<td>标题</td>
<td>关键字</td>
<td>作者</td>
<td>日期</td>
<td>内容</td>
</tr>
<?php while ( $row = mysql_fetch_assoc( $res )){?>
<tr>
<td><?php echo $row [ 'id' ] ?></td>
<td><?php echo $row [ 'title' ] ?></td>
<td><?php echo $row [ 'keywords' ] ?></td>
<td><?php echo $row [ 'author' ] ?></td>
<td><?php echo date ( "Y-m-d H:i:s" , $row [ 'addtime' ]) ?></td>
<td><?php echo $row [ 'content' ] ?></td>
</tr>
<?php }?>
<tr>
<td colspan= "6" >
<?php
echo " 当前{$page}/{$maxpage}页 共{$totalnum}条" ;
echo " <a href='searchpage.php?page=1{$url}'>首页</a> " ;
echo "<a href='searchpage.php?page=" .( $page -1). "{$url}'>上一页</a>" ;
echo "<a href='searchpage.php?page=" .( $page +1). "{$url}'>下一页</a>" ;
echo " <a href='searchpage.php?page={$maxpage}{$url}'>尾页</a> " ;
?>
</td>
</tr>
</table>
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希望本文所述对大家PHP程序设计有所帮助。