How to implement previous page and next page in php

php method to implement the previous page and next page: 1. Create a PHP sample file; 2. Through "function GetPreNext($gtype,$table,$catid,$id){...}" The method is to display the previous article and the next article.

The operating environment of this article: windows7 system, PHP7.4 version, DELL G3 computer

How to implement the previous page and next page with php Page?

Example of PHP's simple implementation of the previous page and next page function

This article describes the example of PHP's simple implementation of the previous page and next page function.

The details are as follows:

Organization of ideas:

Many people now use the increase and decrease of id by 1 to realize the previous and next articles. But won’t the article ID be broken? So you need to know what the last ID and personal ID are.

So how to solve this problem? It’s very simple!

Example:

If the ID of this article is 200

<a href="?action=up&id=200">上一篇</a>
<a href="?action=down&id=200">下一篇</a>

If it is to implement the previous article, write the function on the action=up page

$id= $_GET['id'];
//上一篇：
$sql= select * from article where id < &#39;.$id.&#39; order by id desc limit 0,1&#39;;
$rs= mysql_query($sql);
$row= mysql_fetch_array ($rs);
//下一篇：
$sql= select * from article where id < &#39;.$id.&#39; order by id asc limit 0,1&#39;;
$rs= mysql_query($sql);
$row= mysql_fetch_array ($rs);

Principle, Query 1 piece of data (limit 0,1) that is smaller than the current ID (where id < '.$id.' previous article) and larger than the current ID (where id > '.$id.' next article) , and displayed in descending order (desc, previous article) and ascending order (asc, next article). When only one article is fetched, descending order or ascending order can be omitted.

Specific implementation code: Note that parameters need to be passed

The front desk is called in the previous article and the next article:

<?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[&#39;id&#39;]} " : &#39; where 1>2 &#39;);
  $pre = (is_array($preR) ? " where id={$preR[&#39;id&#39;]} " : &#39; where 1>2 &#39;);
   $query = "Select * from ".$table." ";
      $nextRow =mysql_query($query.$next);
      $preRow = mysql_query($query.$pre);
      if($PreNext=mysql_fetch_array($preRow))
      {
       echo $PreNext[&#39;pre&#39;] = "上一篇：<a href=&#39;newsshow.php?id=".$preR[&#39;id&#39;]."&&catid=".$catid."&#39;>".$PreNext[&#39;title&#39;]."</a> ";
      }
      else
      {
       echo $PreNext[&#39;pre&#39;] = "上一篇：没有了 ";
      }
      if($PreNext=mysql_fetch_array($nextRow))
      {
       echo $PreNext[&#39;next&#39;] = "下一篇：<a href=&#39;newsshow.php?id=".$nextR[&#39;id&#39;]."&&catid=".$catid."&#39;>".$PreNext[&#39;title&#39;]."</a> ";
      }
      else
      {
        echo $PreNext[&#39;next&#39;] = "下一篇：没有了 ";
      }
}

The code is available after testing

Recommended Study: "PHP Video Tutorial"

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