在 Laravel 中调用成员函数错误

Question

我正在 Laravel 7 上构建博客，当我尝试创建帖子时出现此错误：

Call to a member function categories() on bool

这是我的控制器中的存储方法：

public function store(Request $request)
    {
        // Validate incoming data
        $this->validate($request, [
            'title' => 'required',
            'image' => 'required',
            'categories' => 'required',
            'body' => 'required',
        ]);

        $data = array();
        $data['title'] = $request->title;
        $data['slug'] = str_slug($request->title);
        $data['user_id'] = Auth::id();
        $data['meta_title'] = $request->meta_title;
        $data['meta_description'] = $request->meta_description;
        $image = $request->file('image');
        $data['body'] = $request->body;
        $data['created_at'] = \Carbon\Carbon::now();

        $slug = str_slug($request->title);
        
        if($image) {
            $image_name = $slug . "-" . date('dmy_H_s_i');
            $ext = strtolower($image->getClientOriginalExtension());
            $image_full_name = $image_name . '.' . $ext;

            $upload_path = "public/assets/frontend/uploads/posts/";
            $image_url = $upload_path . $image_full_name;
            $success = $image->move($upload_path, $image_full_name);

            $data['image'] = $image_url;
            $post = DB::table('posts')->insert($data);
            

            $post->categories()->attach($request->categories);
            return redirect(route('admin.posts.index'))->with('successMsg', 'Post has been saved successfully!');
        }
}

laravel报错页面有这行有问题：

$post->categories()->attach($request->categories);

我的数据库中有一个单独的表来连接帖子 ID 和类别 ID，它被称为 category_post 除了 category_post 表中的新记录外，帖子内容被插入到数据库中

那么如何更改该代码以使其正常工作？ 谢谢

Answer 1

DB::table('posts')->insert($data);

根据查询的成功/失败执行返回true|false。如果你想这样写

$post->categories()->attach($request->categories);

然后你需要模式 Post 并像这样创建实例：

$post = new Post;
$post->title = $request->title;
// ...
$post->save();

然后您将拥有Post 类的实例