Php 我需要将此类别和子类别的所有产品带到最终级别

我需要带上所有类别和子类别的所有产品。它是如何工作的，这个代码有什么问题

这是一个我需要更正的函数，我将把它放在分页代码和jQuery代码中，jQuery代码将过滤对应于价格低和价格高的最新最老产品

<?php
            function listproducts ($category_img=filter_var($_GET['category'],FILTER_SANITIZE_NUMBER_INT)){
                global $conn;
                $sql_cat_name="select * from categories where cat_id='$category_img' or cat_id in (select cat_id from categories where cat_parent_id='$category_img')";
                $query_cat_name=mysqli_query($conn,$sql_cat_name);
                while($result_cat_name=mysqli_fetch_array($query_cat_name)){
                    $ref_id=$result_cat_name['cat_id'];
                    $show_all_pro="select * from products where product_category='$ref_id'";
                    $query_show_all=mysqli_query($conn,$show_all_pro);
                    while($result_show_all=mysqli_fetch_array($query_show_all)){
                ?>
                <!-- 12 product.-->
            <div class="category-product-inner wow fadeInUp">
              <div class="products">
                <div class="product-list product">
                  <div class="row product-list-row">
                    <div class="col col-sm-4 col-lg-4">
                      <div class="product-image">
                        <div class="image"> <img src="assets/images/products/p3.jpg" alt=""> </div>
                      </div>
                      <!-- /.product-image --> 
                    </div>
                    <!-- /.col -->
                    <div class="col col-sm-8 col-lg-8">
                      <div class="product-info">
                        <h3 class="name"><a href="detail.html">Floral Print Buttoned</a></h3>
                        <div class="rating rateit-small"></div>
                        <div class="product-price"> <span class="price"> $450.99 </span> <span class="price-before-discount">$ 800</span> </div>
                        <!-- /.product-price -->
                        <div class="description m-t-10">Suspendisse posuere arcu diam, id accumsan eros pharetra ac. Nulla enim risus, facilisis bibendum gravida eget, lacinia id purus. Suspendisse posuere arcu diam, id accumsan eros pharetra ac. Nulla enim risus, facilisis bibendum gravida eget.</div>
                        <div class="cart clearfix animate-effect">
                          <div class="action">
                            <ul class="list-unstyled">
                              <li class="add-cart-button btn-group">
                                <button class="btn btn-primary icon" data-toggle="dropdown" type="button"> <i class="fa fa-shopping-cart"></i> </button>
                                <button class="btn btn-primary cart-btn" type="button">Add to cart</button>
                              </li>
                              <li class="lnk wishlist"> <a class="add-to-cart" href="detail.html" title="Wishlist"> <i class="icon fa fa-heart"></i> </a> </li>
                              <li class="lnk"> <a class="add-to-cart" href="detail.html" title="Compare"> <i class="fa fa-signal"></i> </a> </li>
                            </ul>
                          </div>
                          <!-- /.action --> 
                        </div>
                        <!-- /.cart --> 
                      </div>
                      <!-- /.product-info --> 
                    </div>
                    <!-- /.col --> 
                  </div>
                  <!-- /.product-list-row -->
                  <div class="tag new"><span>new</span></div>
                </div>
                <!-- /.product-list --> 
              </div>
              <!-- /.products --> 
            </div>
            <!-- /.category-product-inner -->
                <?
                    }
                    listproducts ($result_cat_name['cat_id']);
                }
            }
            echo listproducts();
        ?>

---

以这种方式显示html代码只能在函数外部工作。
如果您真的想这样做，您需要将html代码放入一个
echo
，这样：

<?php
function listproducts ($category_img=filter_var($_GET['category'],FILTER_SANITIZE_NUMBER_INT)){
    global $conn;
    $sql_cat_name="select * from categories where cat_id='$category_img' or cat_id in (select cat_id from categories where cat_parent_id='$category_img')";
    $query_cat_name=mysqli_query($conn,$sql_cat_name);
    while($result_cat_name=mysqli_fetch_array($query_cat_name)){
        $ref_id=$result_cat_name['cat_id'];
        $show_all_pro="select * from products where product_category='$ref_id'";
        $query_show_all=mysqli_query($conn,$show_all_pro);
        while($result_show_all=mysqli_fetch_array($query_show_all)){
            echo '
            <!-- 12 product.-->
            <div class="category-product-inner wow fadeInUp">
                <div class="products">
                    <div class="product-list product">
                        <div class="row product-list-row">
                            <div class="col col-sm-4 col-lg-4">
                                <div class="product-image">
                                    <div class="image"> <img src="assets/images/products/p3.jpg" alt=""> </div>
                                </div>
                                <!-- /.product-image -->
                            </div>
                            <!-- /.col -->
                            <div class="col col-sm-8 col-lg-8">
                                <div class="product-info">
                                    <h3 class="name"><a href="detail.html">Floral Print Buttoned</a></h3>
                                    <div class="rating rateit-small"></div>
                                    <div class="product-price"> <span class="price"> $450.99 </span> <span class="price-before-discount">$ 800</span> </div>
                                    <!-- /.product-price -->
                                    <div class="description m-t-10">Suspendisse posuere arcu diam, id accumsan eros pharetra ac. Nulla enim risus, facilisis bibendum gravida eget, lacinia id purus. Suspendisse posuere arcu diam, id accumsan eros pharetra ac. Nulla enim risus, facilisis bibendum gravida eget.</div>
                                    <div class="cart clearfix animate-effect">
                                        <div class="action">
                                            <ul class="list-unstyled">
                                                <li class="add-cart-button btn-group">
                                                    <button class="btn btn-primary icon" data-toggle="dropdown" type="button"> <i class="fa fa-shopping-cart"></i> </button>
                                                    <button class="btn btn-primary cart-btn" type="button">Add to cart</button>
                                                </li>
                                                <li class="lnk wishlist"> <a class="add-to-cart" href="detail.html" title="Wishlist"> <i class="icon fa fa-heart"></i> </a> </li>
                                                <li class="lnk"> <a class="add-to-cart" href="detail.html" title="Compare"> <i class="fa fa-signal"></i> </a> </li>
                                            </ul>
                                        </div>
                                        <!-- /.action -->
                                    </div>
                                    <!-- /.cart -->
                                </div>
                                <!-- /.product-info -->
                            </div>
                            <!-- /.col -->
                        </div>
                        <!-- /.product-list-row -->
                        <div class="tag new"><span>new</span></div>
                    </div>
                    <!-- /.product-list -->
                </div>
                <!-- /.products -->
            </div>
            <!-- /.category-product-inner -->
            ';
        }
        listproducts ($result_cat_name['cat_id']);
    }
}
echo listproducts();
?>


代码没有发生任何变化另一件事是我用laravel做的，我看到有一个递归循环来做这个，你能告诉我怎么做这个函数吗