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php实现分类功能实现

2026-01-30 04:52:11PHP

PHP 实现分类功能

数据库设计

创建分类表 categories，包含基本字段：

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

parent_id 用于实现多级分类，指向父分类的 ID。

添加分类

通过表单提交分类数据并插入数据库：

// 处理表单提交
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $name = $_POST['name'];
    $parent_id = $_POST['parent_id'] ?? null;

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

显示分类树

递归查询并显示多级分类：

function displayCategories($parent_id = null, $level = 0) {
    global $pdo;
    $stmt = $pdo->prepare("SELECT * FROM categories WHERE parent_id " . ($parent_id ? "= ?" : "IS NULL"));
    $stmt->execute($parent_id ? [$parent_id] : []);

    while ($category = $stmt->fetch()) {
        echo str_repeat("&nbsp;", $level * 4) . $category['name'] . "<br>";
        displayCategories($category['id'], $level + 1);
    }
}

分类下拉菜单

生成用于表单选择的分类下拉菜单：

function generateCategoryOptions($parent_id = null, $level = 0) {
    global $pdo;
    $stmt = $pdo->prepare("SELECT * FROM categories WHERE parent_id " . ($parent_id ? "= ?" : "IS NULL"));
    $stmt->execute($parent_id ? [$parent_id] : []);

    while ($category = $stmt->fetch()) {
        echo '<option value="' . $category['id'] . '">' . str_repeat("&nbsp;", $level * 4) . $category['name'] . '</option>';
        generateCategoryOptions($category['id'], $level + 1);
    }
}

分类关联

将内容与分类关联：

CREATE TABLE articles (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    content TEXT,
    category_id INT,
    FOREIGN KEY (category_id) REFERENCES categories(id)
);

查询分类内容

获取特定分类下的内容：

$category_id = $_GET['category_id'] ?? null;
$stmt = $pdo->prepare("SELECT * FROM articles WHERE category_id = ?");
$stmt->execute([$category_id]);
$articles = $stmt->fetchAll();

分类面包屑导航

显示当前分类的路径：

php实现分类功能实现

function getBreadcrumbs($category_id) {
    global $pdo;
    $breadcrumbs = [];
    while ($category_id) {
        $stmt = $pdo->prepare("SELECT * FROM categories WHERE id = ?");
        $stmt->execute([$category_id]);
        $category = $stmt->fetch();
        $breadcrumbs[] = $category;
        $category_id = $category['parent_id'];
    }
    return array_reverse($breadcrumbs);
}