我从 MySQLi 数据中获取产品以及如何在输入类型的帮助下对结果中的产品进行排序

Question

<div class="row item-display">
<?php
if(isset($_GET['offers'])){
$cpro_query ="SELECT * FROM product WHERE offers!='no offers'";
}elseif(isset($_POST['search-title'])){
$search =$_POST['search-title'];
$cpro_query ="SELECT * FROM product WHERE tag LIKE '%$search%'";
}
else{
$cpro_query = "SELECT * FROM product";
}
if(isset($cat_name)){
$cpro_query.=" WHERE cat_name='$cat_name'";
}elseif(isset($brand_name)){
$cpro_query.=" WHERE brand_name='$brand_name'";
}else{
$cpro_query.=" ORDER BY product_id DESC";
}
$cpro_run = mysqli_query($con,$cpro_query);
if(mysqli_num_rows($cpro_run)>0){
while ($cpro_row = mysqli_fetch_array($cpro_run)) {
$pro_id = $cpro_row['product_id'];
$pro_title = $cpro_row['title'];
$pro_image = $cpro_row['image1'];
$pro_desc = substr($cpro_row['description'],0,100);
$pro_cost = $cpro_row['cost'];
$pro_rating = $cpro_row['rating'];
?>
<div class="col-md-3">
<a href='single-item-display.php?pro_id=<?php echo $pro_id; ?>'><div class="panel">
<img src="images/<?php echo $pro_image;?>" class="img-responsive center-block" alt="item" >
<p><?php echo $pro_desc;?></p>
<p>Price:<span class="fa fa-rupee"><?php echo $pro_cost;?>/-</span></p>
<p><?php require('inc/rating.php');?></p>
<h4 style="color:#E80C4F;"><?php echo $pro_title;?></h4>
</div></a>
</div>
<?php
}
}else{
echo "<center><span style='color:red;'>No products yet<span></center>";
}
?>
</div>
<ul class="dropdown-menu">
<li class="dropdown">
<a href="product-categorywise.php?lh=<?php echo $lh;?>">Price Low to High </a>
<a href="product-categorywise.php?hl=<?php echo $hl?>">Price High to Low </a>
<a href="product-categorywise.php?fa=<?php echo $lh?>">Fresh Arrivals </a>
<a href="product-categorywise.php?di=<?php echo $lh?>">Discount </a>
</li>
</ul>

如何在结果产品中从价格从高到低或从低到高对产品进行排序。而不是从数据库中的所有产品中排序。我有按颜色、品牌、类型、尺寸排序的列表，例如 this.so 如何编写查询或如何使功能。？

Answer 1

只需添加查询，例如
$cpro_query.=" 按product_id DESC，价格DESC"排序;//按产品 ID 和价格排序为描述订单

Answer 2

$orderfield = 'product_id';
if (isset($_GET['orderfield'])) {
if ($_GET['orderfield']=='someotherfield') {
$orderfield = 'someotherfield';
}
}
$orderdir = 'DESC';
if (isset($_GET['orderdir'])) {
if ($_GET['orderdir']=='asc') {
$orderdir = 'ASC';
}
}
$cpro_query.=" ORDER BY ' . $orderfield . ' ' . $orderdir;