Laravel 多对多节省答案

【问题标题】：Laravel Many To Many SaveLaravel 多对多节省
【发布时间】：2016-08-27 13:23:07
【问题描述】：

我有标签和帖子模型。

迁移标签

class CreateTagsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('tags', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->timestamps();
        });
        Schema::create('post_tag', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('post_id')->unsigned();
            $table->integer('tag_id')->unsigned();

            $table->foreign('post_id')->references('id')->on('posts')->onDelete('cascade');
            $table->foreign('tag_id')->references('id')->on('tags')->onDelete('cascade');
            $table->timestamp();
        });

    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::drop('tags');
        schema::drop('post_tag');
    }
}

迁移帖

class CreatePostsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('posts', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('user_id')->unsigned();
            $table->string('title');
            $table->text('body');
            $table->text('filename');
            $table->timestamps();

    });
}

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
         Schema::drop('posts');
    }
}

应用\标签

class Tag extends Model
{
    protected $table="tags";
    public $timestamps = true;


    protected $fillable = ['name'];

    /**
     * @return \Illuminate\Database\Eloquent\Relations\BelongsToMany
     * Many to Many relations make with post
     */
    public function posts()
    {
        return $this->belongsToMany('App\Post','post_tag','post_id');
    }
}

应用\发布

class Post extends Model
{

    protected $table="posts";
    public $timestamps = true;


    protected $fillable = ['title', 'body', 'filename'];

    /**
     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
     * one to many relationship with user
     */
    public function user()
    {
        return $this->belongsTo('App\User','user_id');
    }

    /**
     * @return BelongsToMany relationship with tags
     * 
     */
    public function tags()
    {
        return $this->belongsToMany('App\Tag','post_tag','tag_id')->withTimestamps();

    }


}

我想附加帖子和标签。有创建帖子表单，我想要这个表单附加标签。我会怎么做？

PostController@store

public function store(Request $request)
{
    \Auth::user()->posts()->save(new Post($request->all()));
    return \Redirect::route('posts.index');
}

我在 Laravel 文档中找到但我不使用方法

App\User::find(1)->roles()->save($role, ['expires' => $expires]);

【问题讨论】：

这有点令人困惑，您能否进一步澄清一下？您展示了您的Post 和Tag 模型，但看起来您将Post 附加到您的User，然后将Role 附加到您的User。不清楚你到底在问什么。
你是对的。我编辑这个问题
我已编辑。我想附上帖子和标签
我相信您应该将附加用于多对多关系。查看文档以获取更多信息：laravel.com/docs/5.2/…

标签： php laravel laravel-5 many-to-many has-and-belongs-to-many

【解决方案1】：

使用同步方式：

App\User::find(1)->roles()->sync($roles);

当 $roles 是角色 ID 数组时：

$roles = [
    0 => '1', // role_id 1
    1 => '2', // role_id 2
    2 => '5', // role_id 5
];

在文档 https://laravel.com/docs/5.2/eloquent-relationships#inserting-many-to-many-relationships

中搜索 Syncing For Convenience

【讨论】：