筛选产品价格和排序 Asc Desc PHP MYSQLI

Question

我希望你永远关心！ 我被问到：

1. 如果我按价格 MIN 到 MAX 过滤产品，可以查看已经OK

2. 在步骤过滤器（第 1 号）和过滤器 ASC 之后，DESC 条件为什么我的视图页面是“为 foreach() 提供的参数无效”，为什么会这样？？？

.

<?php 
    include("config.php");
    $all_brand=$db->query("SELECT distinct brand FROM `products` WHERE category_id = '1' GROUP BY brand");
    // Filter query
    $sql= "SELECT distinct * FROM `products` WHERE category_id = '1'";

    if(isset($_GET['brand']) && $_GET['brand']!="") :
        $sql.=" AND brand IN ('".implode("','",$_GET['brand'])."')";
    endif;

    if(isset($_GET['sort_price']) && $_GET['sort_price']!="") :
        if($_GET['sort_price']=='price-asc-rank') :
            $sql.=" ORDER BY price ASC";
        elseif($_GET['sort_price']=='price-desc-rank') :
            $sql.=" ORDER BY price DESC";
        endif;
    endif;

    // filter by input price
    if(isset($_GET['min']) && $_GET['min']!="") :
     $sql.="AND price >= '".$_GET['min']."' ";
    endif;

    if(isset($_GET['max']) && $_GET['max']!="") :
     $sql.="AND price <= '".$_GET['max']."' ";
    endif;

    $all_product=$db->query($sql);
    ?>

和我的表格：

    *******filter ASC and DESC **********
<div class="panel list">                  
                      <div class="col-sm-2">
                            <select name="sort_price" class="sort_rang" id="sort">
                                 <option value="">Paling baru</option>
                      <option <?=(isset($_GET['sort_price'])&&($_GET['sort_price']=='price-asc-rank')? 'selected="selected"' : '' )?>  value="price-asc-rank">Harga:Rendah ke tinggi </option>

                      <option <?=(isset($_GET['sort_price'])&&($_GET['sort_price']=='price-desc-rank') ? 'selected="selected"' : '' )?>  value="price-desc-rank">Harga:Tinggi ke rendah</option>
                            </select>
                      </div>
                    </div>

    <!-- filter price -->
                        <div class="sidebar-row">
                        <h4>RENTANG HARGA</h4>
                              <input type="text" name="min" id="min" placeholder=" Mulai dari harga" onkeypress="return AllowOnlyNumbers(event);" value="<?php echo isset($_GET['min']) ? $_GET['min'] : ''; ?>"> <br>
                                <br>
                              <input type="text" name="max" id="max" placeholder=" Sampai dgn harga" onkeypress="return AllowOnlyNumbers(event);" value="<?php echo isset($_GET['max']) ? $_GET['max'] : ''; ?>"> <br>
                                <br>
                              <input type="submit" class="sort_rang" value="Tampilkan">
                        </div> 

Answer 1

您不能将价格 WHERE 放在 ORDER 之后：

include("config.php");
$all_brand=$db->query("SELECT distinct brand FROM `products` WHERE category_id = '1' GROUP BY brand");
// Filter query
$sql= "SELECT distinct * FROM `products` WHERE category_id = '1'";

if(isset($_GET['brand']) && $_GET['brand']!="")
    $sql.=" AND brand IN ('".implode("','",$_GET['brand'])."')";

// filter by input price
if(isset($_GET['min']) && $_GET['min']!="")
    $sql.="AND price >= '".$_GET['min']."' ";

if(isset($_GET['max']) && $_GET['max']!="")
    $sql.="AND price <= '".$_GET['max']."' ";

if(isset($_GET['sort_price']) && $_GET['sort_price']!="") :
    if($_GET['sort_price']=='price-asc-rank')
        $sql.=" ORDER BY price ASC";
    elseif($_GET['sort_price']=='price-desc-rank')
        $sql.=" ORDER BY price DESC";
endif;


$all_product=$db->query($sql);

顺便说一句：您的代码存在 SQL 注入漏洞。这很糟糕，了解更多：http://bobby-tables.com/php