在 Laravel 中調用成員函數錯誤

Question

我正在 Laravel 7 上建立一個博客，當我嘗試創建一個帖子時，我收到此錯誤：

Call to a member function categories() on bool

這是我的控制器中的 store 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 錯誤頁面有這行有問題：

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

我的數據庫中有一個單獨的表，用於將帖子ID 與類別ID 連接起來，稱為category_post 除了category_post 表中的新記錄外，將帖子內容插入到數據庫中

那么如何更改該代碼以使其正常工作？ 謝謝

Answer 1

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

根據查詢的成功/失敗執行返回true|false 。 如果你想寫

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

然后你需要模式Post並創建這樣的實例：

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

然后你將擁有Post類的實例