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php实现分类

2026-02-13 13:17:14PHP

PHP实现分类的方法

数据库设计

创建分类表通常需要包含id、名称、父级id等字段。以下是一个基本的SQL示例：

CREATE TABLE categories (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    parent_id INT DEFAULT NULL,
    FOREIGN KEY (parent_id) REFERENCES categories(id) ON DELETE CASCADE
);

递归获取分类树

使用递归函数获取无限级分类结构：

php实现分类

function getCategories($parentId = null) {
    $categories = [];
    $query = "SELECT * FROM categories WHERE parent_id " . ($parentId ? "= $parentId" : "IS NULL");
    $result = mysqli_query($connection, $query);

    while ($row = mysqli_fetch_assoc($result)) {
        $row['children'] = getCategories($row['id']);
        $categories[] = $row;
    }

    return $categories;
}

分类展示

在HTML中展示分类可以使用嵌套列表：

php实现分类

function displayCategories($categories) {
    echo '<ul>';
    foreach ($categories as $category) {
        echo '<li>' . htmlspecialchars($category['name']);
        if (!empty($category['children'])) {
            displayCategories($category['children']);
        }
        echo '</li>';
    }
    echo '</ul>';
}

添加分类

实现添加分类的表单处理：

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $name = $_POST['name'];
    $parentId = $_POST['parent_id'] ?: null;

    $stmt = $pdo->prepare("INSERT INTO categories (name, parent_id) VALUES (?, ?)");
    $stmt->execute([$name, $parentId]);
}

使用ORM实现

使用Laravel的Eloquent模型可以简化操作：

class Category extends Model {
    public function children() {
        return $this->hasMany(Category::class, 'parent_id');
    }

    public function parent() {
        return $this->belongsTo(Category::class, 'parent_id');
    }
}

// 获取所有分类
$categories = Category::with('children')->whereNull('parent_id')->get();