本文实例讲述了PHP简单实现上一页下一页功能。分享给大家供大家参考,具体如下:
思路整理:
现在好多人用id的增1和减1实现上一篇和下一篇,但是难道文章ID不会断了吗?所以你要知道上个ID和个ID是多少就OK了。
那怎么解决这个问题呢,很简单!
例子:
假如这篇文章的ID200
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< a href = "?action=up&id=200" >上一篇</ a > < a href = "?action=down&id=200" >下一篇</ a > |
如果是实现上一篇就在action=up页面写函数
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$id = $_GET [ 'id' ]; //上一篇: $sql = select * from article where id < '.$id.' order by id desc limit 0,1'; $rs = mysql_query( $sql ); $row = mysql_fetch_array ( $rs ); //下一篇: $sql = select * from article where id < '.$id.' order by id asc limit 0,1'; $rs = mysql_query( $sql ); $row = mysql_fetch_array ( $rs ); |
原理,查询比当前ID小(where id < '.$id.'上一篇)和比当前ID大(where id > '.$id.'下一篇)的1条(limit 0,1)数据,并按降序(desc,上一篇)和升序(asc,下一篇)显示出来,当只取一篇的时候,可以省略降序或升序。
具体实现代码:注需要传递参数
前台在上一篇,下一篇处调用:
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<?php echo GetPreNext(pre,news, $_REQUEST [catid], $_REQUEST [id]);?> //显示上一篇下一篇 function GetPreNext( $gtype , $table , $catid , $id ){ $preR =mysql_fetch_array(mysql_query( "select * from " . $table . " where catid=" . $catid . " and id<$id order by id desc limit 0,1" )); //id比传入id小的最近一条 $nextR =mysql_fetch_array(mysql_query( "select * from " . $table . " where catid=" . $catid . " and id>$id order by id asc limit 0,1" )); //id比传入id大的最近一条 $next = ( is_array ( $nextR ) ? " where id={$nextR['id']} " : ' where 1>2 ' ); $pre = ( is_array ( $preR ) ? " where id={$preR['id']} " : ' where 1>2 ' ); $query = "Select * from " . $table . " " ; $nextRow =mysql_query( $query . $next ); $preRow = mysql_query( $query . $pre ); if ( $PreNext =mysql_fetch_array( $preRow )) { echo $PreNext [ 'pre' ] = "上一篇:<a href='newsshow.php?id=" . $preR ['id ']."&&catid=".$catid."' >". $PreNext [ 'title' ]. "</a> " ; } else { echo $PreNext [ 'pre' ] = "上一篇:没有了 " ; } if ( $PreNext =mysql_fetch_array( $nextRow )) { echo $PreNext [ 'next' ] = "下一篇:<a href='newsshow.php?id=" . $nextR ['id ']."&&catid=".$catid."' >". $PreNext [ 'title' ]. "</a> " ; } else { echo $PreNext [ 'next' ] = "下一篇:没有了 " ; } } |
代码经测试可用
希望本文所述对大家PHP程序设计有所帮助。