大家好，我已经写了分页代码，该代码在localhost上是正确的，但是当我将其上传到服务器上时，它不起作用，只是显示“无产品”，因为我在其他条件下写它请帮助我解决此问题，因为此页面上的所有操作都正常，只是没有显示产品。
<?php
include "database.php";
$id=$_GET['category_id'];
$res= mysqli_query($link, "SELECT * from product where category_id= '$id' ORDER BY product_id DESC ;");
$result_per_page = 5;
$number_of_result = mysqli_num_rows($res);
$number_of_pages = ceil($number_of_result/$result_per_page);
if(!isset($_GET['page'])){
$page = 1;
}
else{
$page = $_GET['page'];
}
$this_page_first_result = ($page-1)*$result_per_page;
$sql = "SELECT * FROM PRODUCT where category_id= '$id' LIMIT ".$this_page_first_result .','. $result_per_page;
$result = mysqli_query($link, $sql);
if(mysqli_num_rows($result)> 0){
while($row=mysqli_fetch_array($result)){
?>
<div class="col-md-3 col-xs-6" >
<a href="product.php?product_id=<?php echo $row["product_id"]; ?>" ><div class="product" style=" height: 426px;">
<div class="product-img">
<img src="admin/<?php echo $row["product_image"]; ?>" alt="" style="height:200px;">
<div class="product-label">
</div>
</div>
<div class="product-body">
<p class="product-category"><?php echo $row["category_id"]; ?></p>
<div >
<h3 class="product-name" ><?php echo $row["brand"]; ?></h3>
</div>
<h3 class="product-name"><a href="product.php?product_id=<?php echo $row["product_id"]; ?>"><?php echo $row["product_name"]; ?></a></h3>
<?php
if($row["product_price"] < $row["ali_price"] && $row["product_price"] < $row["amazon_price"]){
?>
<h4 class="product-price">$<?php echo $row["product_price"]; ?> </h4>
<?php
}
else if ($row["ali_price"] < $row["product_price"] && $row["ali_price"] < $row["amazon_price"]) {
?>
<h4 class="product-price">$<?php echo $row["ali_price"]; ?> </h4>
<?php
}
else if ($row["amazon_price"] < $row["product_price"] && $row["amazon_price"] < $row["ali_price"]){
?>
<h4 class="product-price">$<?php echo $row["amazon_price"]; ?> </h4>
<?php
}
?>
</div>
</div> </a>
</div>
<?php
}
}
else{
echo "<h1><center>No Product Available!</center></h1>";
?>
<?php
}
?>
<div class="store-filter clearfix">
<ul class="store-pagination">
<?php
for($page=1 ; $page<=$number_of_pages; $page++){
echo '<li><a href="store.php?category_id='.$id.'&page='.$page.'">'.$page. '</a></li>';
?>
</ul>
</div><!-- /store bottom filter -->
我希望输出将显示所有具有相关类别的产品。