一個用戶可能有多個文章，一個文章是某個用戶書寫的，這就是關系。同樣文章中可能包含多個 TAG，而一個 TAG 可能關聯多個文章。

在項目中，我們已經有了 User.php，也就是用戶模型，查看一下，相當簡單。我們希望直接使用 $user->articles() 的形式獲取全部文章，讓我們修改 user 模型：

    public function articles() {        return $this->hasMany('App/Article');    }

但是我們僅僅完成了關系中的一端，讓我們來處理另一端。我們希望的形式是 $article->user() ，讓我們修改 article 模型。

    public function user() {        return $this->belongsTo('App/User');    }

在我們的數據庫中，文章模型沒有用戶的外鍵，我們需要設置，修改 create_article_table.php

Schema::create('articles', function(BluePRint $table){$table->increments('id');            //指定外鍵列            $table->integer('user_id')->unsigned();            $table->string('title');            $table->text('body');            $table->timestamp('published_at');$table->timestamps();            //生成外鍵            $table->foreign('user_id')                ->references('id')                ->on('users')                ->onDelete('cascade');});

因為我們只是在開發階段，還沒有上線運行，我們可以直接修改數據庫遷移文件，回滾然后遷移即可，但是如果上線運行的話，應該新建一個遷移。

php artisan migrate:refresh#輸出信息Rolled back: 2015_03_28_050138_create_article_tableRolled back: 2014_10_12_100000_create_passWord_resets_tableRolled back: 2014_10_12_000000_create_users_tableNothing to rollback.Migrated: 2014_10_12_000000_create_users_tableMigrated: 2014_10_12_100000_create_password_resets_tableMigrated: 2015_03_28_050138_create_article_tableMigrated: 2015_03_28_051200_add_excerpt_to_articels_table

現在讓我們使用 tinker 來創建一個用戶。

php artisan tinkerPsy Shell v0.4.1 (PHP 5.4.16 — cli) by Justin Hileman#下面是執行過程>>> $user = new App/User;=> <App/User #000000007f1ad61a000000006497cc4f> {}>>> $user->name = 'zhang jinglin';=> "zhang jinglin">>> $user->email = 'zjl@example.com';=> "zjl@example.com">>> $user->password = bcrypt('pass');=> "$2y$10$Nbl2b9wqd.rXqKEsd3pRSOoIyFAFIhbqf71BufwDfS3Guv21SlEx2">>> $user->save();=> true>>> App/User::first()->toArray();=> [       "id"         => "1",       "name"       => "zhang jinglin",       "email"      => "zjl@example.com",       "created_at" => "2015-03-31 03:24:55",       "updated_at" => "2015-03-31 03:24:55"   ]>>> 

現在我們需要新發布的文章和用戶關聯，我們暫時先修改 form_partial.blade.php 來隱藏一個用戶id，只是暫時：

{{--臨時處理--}}{!! Form::hidden('user_id', 1) !!}

同時要修改模型的 $fillabel 屬性，以便我們的 Mass Assisment。

protected $fillable = [        'title',        'body',        'published_at',        'user_id' //臨時設置    ];

OK，添加一個文章。我們使用 tinker 來查看一下。

php artisan tinkerPsy Shell v0.4.1 (PHP 5.4.16 — cli) by Justin Hileman>>> App/Article::first()->toArray();=> [       "id"           => "1",       "user_id"      => "1",       "title"        => "User 1 Article",       "body"         => "User 1 Body",       "published_at" => "2015-03-31 08:00:00",       "created_at"   => "2015-03-31 04:17:58",       "updated_at"   => "2015-03-31 04:17:58",       "excerpt"      => null   ]#獲取用戶>>> $user = App/User::first();=> <App/User #0000000051cbb9d70000000073e11a3e> {       id: "1",       name: "zhang jinglin",       email: "zjl@example.com",       created_at: "2015-03-31 03:24:55",       updated_at: "2015-03-31 03:24:55"   }#獲取用戶文章>>> $user->articles()->toArray();BadMethodCallException with message 'Call to undefined method Illuminate/Database/Query/Builder::toArray()'>>> $user->articles->toArray();=> [       [           "id"           => "1",           "user_id"      => "1",           "title"        => "User 1 Article",           "body"         => "User 1 Body",           "published_at" => "2015-03-31 08:00:00",           "created_at"   => "2015-03-31 04:17:58",           "updated_at"   => "2015-03-31 04:17:58",           "excerpt"      => null       ]   ]   #為什么使用 $user->articles 而不是 #user->articles()?#事實上，$user->articles()返回的是關系，如果你想用 articles() 你需要這樣用>>> $user->articles()->get()->toArray();=> [       [           "id"           => "1",           "user_id"      => "1",           "title"        => "User 1 Article",           "body"         => "User 1 Body",           "published_at" => "2015-03-31 08:00:00",           "created_at"   => "2015-03-31 04:17:58",           "updated_at"   => "2015-03-31 04:17:58",           "excerpt"      => null       ]   ]   #你只能使用 articles() 來進行下一步的工作，比如下面的查詢$user->articles()->where('title', 'User 1 Article')->get();#我們也可以通過 article 獲取 user>>> $article = App/Article::first();=> <App/Article #0000000051cbb9d60000000073e11a3e> {       id: "1",       user_id: "1",       title: "User 1 Article",       body: "User 1 Body",       published_at: "2015-03-31 08:00:00",       created_at: "2015-03-31 04:17:58",       updated_at: "2015-03-31 04:17:58",       excerpt: null   }>>> $article->user;=> <App/User #0000000051cbb92d0000000073e11a3e> {       id: "1",       name: "zhang jinglin",       email: "zjl@example.com",       created_at: "2015-03-31 03:24:55",       updated_at: "2015-03-31 03:24:55"   }>>>