Lavarel 快速學習自我挑戰 Day5

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Eloquent Relationship - Eloquent Relationship 設定官方文件

1. One to One Relationship
   • 新增 user_id 到 migration
     $table->integer('user_id')->unsigned();
   • 新增一個 function 到 User.php
     public function post(){return $this->hasOne('App\Post');}
   • 新增 routes
     Route::get('/user/{id}/post', function($id){return User::find($id)->post->title;});
2. Reverse One to One Relationship (Inverse Relationship)
   • 新增一個 function 到 Post.php
     public function user(){return $this->belongsTo('App\User');}
   • 新增 routes
     Route::get('/user/{id}/post', function($id){return User::find($id)->post->content;});
3. One to Many Relationship
   • 新增一個 function 到 User.php
     public function posts(){return $this->hasMany('App\Post');}
   • 新增 routes

    Route::get('/posts', function(){

    $user = User::find(1);

    foreach ($user->posts as $post) {

        echo $post->title ."<br>"; (不要使用 return，return 只能傳回一個內容)

    }

});

4. Many to Many Relationship
   • 新增一個 model
     php artisan make:model Role -m
   • 新增一個 migration
     php artisan make:migration create_users_roles_table --create=role_user
   • 在 create_roles_table 新增姓名
     $table->string('name');
   • 在 create_users_roles_table 新增 user_id 和 role_id
     $table->integer('user_id');
$table->integer('role_id');
   • 在 User.php 新增一個 function
     public function roles(){return $this->belongsToMany('App\Role');}
   • 新增 routes (1)
     Route::get('/user/{id}/role', function($id){
$user = User::find($id);
foreach ($user->roles as $role) {return $role->name;}});
   • 新增 routes (2)
     Route::get('/user/{id}/role', function($id){
$user = User::find($id)->roles()->orderBy('id', 'desc')->get();
return $user;
});
5. 取得 Intermediate table
   • 在 Role.php 新增 belongsToMany
     public function users(){return $this->belongsToMany('App\User');}
   • 在 User.php 的 roles function 新增 withPivot
     return $this->belongsToMany('App\Role')->withPivot('created_at');
   • 新增 routes

Route::get('/user/pivot', function(){

    $user = User::find(1);

    foreach($user->roles as $role){

        return $role->pivot->created_at;

    }

});

6. Has Many Through Relation
   • 新增一個 model
     php artisan make:model Country -m
   • 新增一個 migration
     php artisan make:migration add_country_id_column_to_users --table=users
   • 到 add_country_id_column_to_users.php 的 up function 新增
     $table->integer('country_id');
   • 到 add_country_id_column_to_users.php 的 down function 新增
     $table->dropColumn('country_id');
   • 到 create_countries_table 新增
     $table->string('name');
   • 匯入資料庫
     php artisan migrate
   • 在 Country Model 新增 function
     public function posts(){return $this->hasManyThrough('App\Post', 'App\User');}
   • 在 routes 引入 Model
     use App\Country
   • 新增 routes

Route::get('/user/country', function(){

$country = Country::find(4);

foreach ($country->posts as $post){

    return $post->title;;

}

});

7. Polymorphic Relation
   • 新增 photo 的 Model
     php artisan make:model Photo -m
   • 在 create_photos_table 新增以下欄位
     $table->string('path');
$table->integer('imageable_id');
$table->string('imageable_type');
   • 匯入資料庫
     php artisan migrate
   • 不需要 user_id，在 create_post_talbe 移除並更新
     $table->integer('user_id')->unsigned();
php artisan migrate:refresh
   • 在 Photo.php 新增一個 function
     public function imageable() {return $this->morphTo();}
   • 在 Post.php 和 User.php 各新增一個 function
     public function photos(){return $this->morphMany('App\Photo', 'imageable');}
   • 新增 routes

Route::get('post/{id}/photos', function($id){

    $post = Post::find($id);

        foreach($post->photos as $photo){

            echo $photo->path . "<br>";

        }

});

8. Reverse Polymorphic Relation
   • 在 routes 引入 Model
     use App\Photo;
   • 新增 routes

Route::get('photo/{id}/post', function($id){

    $photo = Photo::findOrFail($id);

    return $photo->imageable;

});

9. Many to Many Polymorphic Relation
   • 新增三個 model
     php artisan make:model Video -m
php artisan make:model Tag -m
php artisan make:model Taggable -m
   • 在 create_videos_table 和 create_tags_table 建立 name 的 table
     $table->string('name');
   • 在 create_taggables_table 建立以下 table
     $table->integer('tag_id');
$table->integer('taggable_id');
$table->string('taggable_type');
   • 在 Post.php 新增 morphToMany function
     public function tags(){return $this->morphToMany('App\Tag', 'taggable');}
   • 在 Tag.php 新增 morphedByMany function
     public function posts(){ return $this->morphedByMany('App\Post', 'taggable');}
public function videos(){return $this->morphedByMany('App\Video', 'taggable');}
   • 匯入 migrate
     php artisan migrate
   • 新增 routes
     Route::get('/post/tag', function(){
$post = Post::find(1);
foreach ($post->tags as $tag){
echo $tag->name;
}
});
   • import Tag model
     use App\Tag;
   • 新增 routes
     Route::get('/tag/post', function(){
$tag = Tag::find(2);
foreach($tag->posts as $post){
return $post->title;
}
});