在布尔值上调用成员函数 attach() - Laravel

Posted 2023-03-15

【中文标题】在布尔值上调用成员函数 attach() - Laravel

【英文标题】：Call to a member function attach() on boolean - Laravel

【发布时间】：2021-05-23 07:42:45

【问题描述】：

我对函数 attach() 有疑问。我创建了 3 个表。 1 个表用于添加电影。表 2 适用于电影类别。 3表是电影ID和类别ID的集合。多对多的组合。

当我想从表单中添加一个带有类别的新视频时，我有错误 -> 在布尔值上调用成员函数 attach()。如果有人知道答案，请帮忙。感谢您的宝贵时间！

VideoController.php -> 查看方法 store();

<?php

namespace App\Http\Controllers;

use Request;
use App\Http\Requests\CreateVideoRequest;
use App\Video;
use App\Category;
use Auth;
use Session;

class VideoController extends Controller

    public function __construct()
        $this->middleware('auth', ['except' => 'index']);
    

    public function index()
        $videos = Video::latest()->get();
        return view('videos.index')->with('videos', $videos);
    

    public function show($id)
        $video = Video::find($id);  
        return view('videos.show')->with('video', $video);
    

    public function create()
        $categories = Category::pluck('name', 'id');
        return view('videos.create')->with('categories',$categories);
    

    public function store(CreateVideoRequest $request)
        $video = new Video($request->all());
        //dd($request->all());
        Auth::user()->videos()->save($video);

        $categoryIds = $request->input('CategoryList');
        $video->categories()->attach($categoryIds);

        Session::flash('video_created', 'Added');

        return redirect('video');
    

    public function edit($id)
        $video = Video::findOrFail($id);
        return view('videos.edit')->with('video', $video);
    

    public function update($id, CreateVideoRequest $request)
        $video = Video::findOrFail($id);
        $video->update($request->all());
        return redirect('video');
    

Video.php - 模型

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Video extends Model
   

    protected $fillable = [
        'title',
        'url',
        'description'
    ];

    public function user()
        return $this->belongsTo('App\User');
    

    public function categories()
        return $this->belongsToMany('App\Video')->withTimestamps;
    

Category.php - 型号

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Category extends Model


    protected $fillable = [ 'name' ];

    public function videos()
        return $this->belongsToMany('App/Video')->withTimestamps;
    

User.php - 模型（也许你需要一个 User.php 模型来解决问题）

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable

    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];

    /**
     * The attributes that should be cast to native types.
     *
     * @var array
     */
    protected $casts = [
        'email_verified_at' => 'datetime',
    ];

    public function videos()
        return $this->hasMany('App\Video');
    

迁移 - create_category_video_table.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateCategoryVideoTable extends Migration

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    
        Schema::create('category_video', function (Blueprint $table) 
            $table->bigIncrements('id');
            $table->unsignedBigInteger('category_id');

            $table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade');
            $table->unsignedBigInteger('video_id');

            $table->foreign('video_id')->references('id')->on('videos')->onDelete('cascade');
            $table->timestamps();
        );
    

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    
        Schema::dropIfExists('category_video');
    

迁移 - create_categories_table.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateCategoriesTable extends Migration

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    
        Schema::create('categories', function (Blueprint $table) 
            $table->bigIncrements('id');
            $table->string('name');
            $table->timestamps();
        );
    

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    
        Schema::dropIfExists('categories');
    

迁移 - create_videos_table.php

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateVideosTable extends Migration

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    
        Schema::create('videos', function (Blueprint $table) 
            $table->bigIncrements('id');
            $table->unsignedBigInteger('user_id');     
            $table->string('title');
            $table->string('url');
            $table->text('description');
            $table->timestamps();

            $table->foreign('user_id')->references('id')->on('users');
        );
    

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    
        Schema::dropIfExists('videos');
    

form.blade.php - Laravel Collection 中的简单表单

!! Form::select('CategoryList', $categories, null, ['multiple' => 'multiple']) !!

【参考方案1】：

对于枢轴的时间戳，您将调用“方法”withTimestamps() 而不是名为 withTimestamps 的“属性”：

// Video
public function categories()

    return $this->belongsToMany(Category::class)->withTimestamps();


// Category
public function videos()

    return $this->belongsToMany(Video::class)->withTimestamps();