一个用户可能有多个文章,一个文章是某个用户书写的,这就是关系。同样文章中可能包含多个 TAG,而一个 TAG 可能关联多个文章。
在项目中,我们已经有了 User.php,也就是用户模型,查看一下,相当简单。我们希望直接使用 $user->articles() 的形式获取全部文章,让我们修改 user 模型:
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public function articles() { return $this ->hasMany( 'App\Article' ); } |
但是我们仅仅完成了关系中的一端,让我们来处理另一端。我们希望的形式是 $article->user() ,让我们修改 article 模型。
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public function user() { return $this ->belongsTo( 'App\User' ); } |
在我们的数据库中,文章模型没有用户的外键,我们需要设置,修改 create_article_table.php
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Schema::create( 'articles' , function (Blueprint $table ) { $table ->increments( 'id' ); //指定外键列 $table ->integer( 'user_id' )->unsigned(); $table ->string( 'title' ); $table ->text( 'body' ); $table ->timestamp( 'published_at' ); $table ->timestamps(); //生成外键 $table ->foreign( 'user_id' ) ->references( 'id' ) ->on( 'users' ) ->onDelete( 'cascade' ); }); |
因为我们只是在开发阶段,还没有上线运行,我们可以直接修改数据库迁移文件,回滚然后迁移即可,但是如果上线运行的话,应该新建一个迁移。
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php artisan migrate:refresh #输出信息 Rolled back: 2015_03_28_050138_create_article_table Rolled back: 2014_10_12_100000_create_password_resets_table Rolled back: 2014_10_12_000000_create_users_table Nothing to rollback. Migrated: 2014_10_12_000000_create_users_table Migrated: 2014_10_12_100000_create_password_resets_table Migrated: 2015_03_28_050138_create_article_table Migrated: 2015_03_28_051200_add_excerpt_to_articels_table |
现在让我们使用 tinker 来创建一个用户。
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php artisan tinker Psy Shell v0.4.1 (PHP 5.4.16 — cli) by Justin Hileman #下面是执行过程 >>> $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" ] >>> |
现在我们需要新发布的文章和用户关联,我们暂时先修改 form_partial.blade.php 来隐藏一个用户id,只是暂时:
{{--临时处理--}}
{!! Form::hidden('user_id', 1) !!}
同时要修改模型的 $fillabel 属性,以便我们的 Mass Assisment。
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protected $fillable = [ 'title' , 'body' , 'published_at' , 'user_id' //临时设置 ]; |
OK,添加一个文章。我们使用 tinker 来查看一下。
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php artisan tinker Psy 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 ] #获取用户 >>> $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" } #获取用户文章 >>> $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 ] ] #为什么使用 $user ->articles 而不是 #user->articles()? #事实上, $user ->articles()返回的是关系,如果你想用 articles() 你需要这样用 >>> $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() 来进行下一步的工作,比如下面的查询 $user ->articles()->where( 'title' , 'User 1 Article' )->get(); #我们也可以通过 article 获取 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" } >>> |
以上所述就是本文的全部内容了,希望大家能够喜欢。