PHP Developer City を使用して製品分類およびフィルタリング機能を実装する方法

CREATE TABLE `category` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
);

CREATE TABLE `subcategory` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  `category_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
);

<?php
// 连接MySQL数据库
$connection = mysqli_connect("localhost", "username", "password", "database");

// 查询所有的一级分类
$query = "SELECT * FROM category";
$result = mysqli_query($connection, $query);

// 将查询结果存储为数组
$categories = array();
while ($row = mysqli_fetch_assoc($result)) {
  $categories[] = $row;
}

// 关闭数据库连接
mysqli_close($connection);
?>

<ul>
  <?php foreach ($categories as $category): ?>
    <li><a href="category.php?id=<?php echo $category['id']; ?>"><?php echo $category['name']; ?></a></li>
  <?php endforeach; ?>
</ul>

<?php
// 连接MySQL数据库
$connection = mysqli_connect("localhost", "username", "password", "database");

// 读取查询字符串中的id参数
$category_id = $_GET['id'];

// 查询该一级分类下的所有二级分类
$query = "SELECT * FROM subcategory WHERE category_id = $category_id";
$result = mysqli_query($connection, $query);

// 将查询结果存储为数组
$subcategories = array();
while ($row = mysqli_fetch_assoc($result)) {
  $subcategories[] = $row;
}

// 关闭数据库连接
mysqli_close($connection);
?>

<ul>
  <?php foreach ($subcategories as $subcategory): ?>
    <li><a href="subcategory.php?id=<?php echo $subcategory['id']; ?>"><?php echo $subcategory['name']; ?></a></li>
  <?php endforeach; ?>
</ul>

<?php
// 连接MySQL数据库
$connection = mysqli_connect("localhost", "username", "password", "database");

// 读取查询字符串中的筛选条件
$category_id = $_GET['category_id'];
$subcategory_id = $_GET['subcategory_id'];

// 根据筛选条件查询相应的商品
$query = "SELECT * FROM products WHERE category_id = $category_id AND subcategory_id = $subcategory_id";
$result = mysqli_query($connection, $query);

// 将查询结果存储为数组
$products = array();
while ($row = mysqli_fetch_assoc($result)) {
  $products[] = $row;
}

// 关闭数据库连接
mysqli_close($connection);
?>