When the main page is completed, the database data needs to be displayed through SQL statements

You need to use the paging function to display it. After all, the number displayed on the first page is limited.

We set 5 pieces of data to be displayed on each page

$pagesize=5;

To obtain the id, you need to sort it in reverse order. The book title category is in Chinese, and the urldecode() function is needed to convert the Chinese into an encoded form.

<?php
if(!urldecode($_GET['proid'])){
   //urldecode()函數(shù)將 URL 編碼后字符串還原成未編碼的樣子。編碼使用 %## 的格式
   $SQL ="SELECT * FROM yx_books order by id desc";  //倒序排列
}else{
   $SQL ="SELECT * FROM yx_books where type='".urldecode($_GET['proid'])."'";
   //將查詢出來(lái)的書目類別中文字轉(zhuǎn)換為編碼形式
}
?>

Get the total number of queried data, calculate the total number of pages, and then judge the current page. When the current page is less than the first page, the first page is displayed. When the current page number is greater than the total number of pages, the total number is displayed. Pages Pages.

Determine which piece of data to start displaying on each page.

<?php
$rs=mysqli_query($link,$sql);
$recordcount=mysqli_num_rows($rs);  //輸出查詢的總數(shù)
//mysql_num_rows() 返回結(jié)果集中行的數(shù)目。此命令僅對(duì) SELECT 語(yǔ)句有效。
$pagecount=($recordcount-1)/$pagesize+1;  //計(jì)算總頁(yè)數(shù)
$pagecount=(int)$pagecount;
$pageno=empty($_GET["pageno"])?'':$_GET["pageno"];  //當(dāng)前頁(yè)

if($pageno=="")  //當(dāng)前頁(yè)為空時(shí)顯示第一頁(yè)
{
   $pageno=1;
}
if($pageno<1)   //當(dāng)前頁(yè)小于第一頁(yè)時(shí)顯示第一頁(yè)
{
   $pageno=1;
}
if($pageno>$pagecount)  //當(dāng)前頁(yè)數(shù)大于總頁(yè)數(shù)時(shí)顯示總頁(yè)數(shù)
{
   $pageno=$pagecount;
}
$startno=($pageno-1)*$pagesize;  //每頁(yè)從第幾條數(shù)據(jù)開始顯示
?>

SELECT queries out the statements in the database and then displays them in a loop:

<?php
if(!urldecode($_GET["proid"])){
   $SQL ="SELECT * FROM yx_books order by id desc limit $startno,$pagesize";
}else{
   $SQL ="SELECT * FROM yx_books where type='".urldecode($_GET['proid'])."' order by id desc limit $startno,$pagesize";
}
$rs=mysqli_query($link,$sql);
?>

<?php
 if(!empty($rs)){
     while($rows=mysqli_fetch_array($rs))
   {
?>
    <tr>
       <td height="30" align="center" bgcolor="#FFFFFF"><?php echo $rows["id"];?></td>
       <td align="center" bgcolor="#FFFFFF"><?php echo $rows["name"];?></td>
       <td align="center" bgcolor="#FFFFFF"><?php echo $rows["price"];?></td>
       <td align="center" bgcolor="#FFFFFF"><?php echo $rows["uploadtime"];?></td>
       <td align="center" bgcolor="#FFFFFF"><?php echo $rows["type"];?></td>
       <td align="center" bgcolor="#FFFFFF"><?php echo $rows["leave_number"];?></td>
       <td align="center" bgcolor="#FFFFFF" class="line2"></td>
    </tr>
<?php
    }
 }
?>

Finally, the functions of clicking the homepage, previous page, next page, and last page are displayed.

If the current page is the first page, only the home page and the previous page will be displayed.

When the current page is the total number of pages, the homepage and previous page are displayed as links.

The rest are displayed as normal added links

<?php
if($pageno==1)
{
   ?>
   首頁(yè) | 上一頁(yè) |
   <?php if($pageno+1<= $pagecount) { ?>
   <a href="index.php?proid=<?php echo empty($_GET['proid']) ? '' : urlencode($_GET['proid']); ?>&pageno=<?php echo $pageno + 1 ?>">下一頁(yè)</a> |
   <a href="index.php?proid=<?php echo empty($_GET['proid']) ? '' : urlencode($_GET['proid']); ?>&pageno=<?php echo $pagecount ?>">末頁(yè)</a>
   <?php
     }
}
else if($pageno==$pagecount)
{
   ?>
   <a href="index.php?proid=<?php echo urlencode($_GET['proid']);?>&pageno=1">首頁(yè)</a> |
   <a href="index.php?proid=<?php echo urlencode($_GET['proid']);?>&pageno=<?php echo $pageno-1?>">上一頁(yè)</a> | 下一頁(yè) | 末頁(yè)
   <?php
}
else
{
   ?>
   <a href="index.php?proid=<?php echo urlencode($_GET['proid']);?>&pageno=1">首頁(yè)</a> |
   <a href="index.php?proid=<?php echo urlencode($_GET['proid']);?>&pageno=<?php echo $pageno-1?>">上一頁(yè)</a> |
   <a href="index.php?proid=<?php echo urlencode($_GET["proid"]);?>&pageno=<?php echo $pageno+1?>" class="forumRowHighlight">下一頁(yè)</a> |
   <a href="?pageno=<?php echo $pagecount?>">末頁(yè)</a>
   <?php
}
?>
&nbsp;頁(yè)次：<?php echo $pageno ?>/<?php echo $pagecount ?>頁(yè)&nbsp;共有<?php echo $recordcount?>條信息