Question

首先，我是 Laravel 的新手，我已经阅读了一些教程和很多文档，但现在我遇到了一个无法找到解决方案的问题。

我有三个表：post，post_adv_option，adv_option。

所以这些表之间的关系是：

post to post_adv_option：One-to-Many
post_adv_option to adv_option：One-to-One

这是我正在使用的代码：

模型

class Post extends Eloquent {
   public function postAdvancedOptions() {
      return $this->hasMany('PostAdvancedOptions','post_id');
   }
}

class PostAdvancedOption extends Eloquent {
   public function AdvancedOption() {
      return $this->hasOne('AdvancedOption','id','advanced_option_id');
   }
}

class AdvancedOption extends Eloquent {

}

表格

Post Table
------------------------------  
| id | title | content | ... |
------------------------------
| 1  | AAAAA | aaaaaaa | ... |
------------------------------
| 2  | BBBBB | bbbbbbb | ... |
------------------------------
| .  | ..... | ....... | ... |
------------------------------

PostAdvancedOption Table 
---------------------------------------------
| id | post_id | advanced_option_id | value |
---------------------------------------------
| 1  | 1       | 2                  | xxxxx |
---------------------------------------------
| 2  | 2       | 1                  | aaaaa |
---------------------------------------------
| 3  | 2       | 4                  | bbbbb |
---------------------------------------------
| 4  | 2       | 5                  | xxxxx |
---------------------------------------------

AdvancedOption Table 
----------------------------------------
| id | name      | sort  | description |
----------------------------------------
| 1  | abc       | 0     | desc        |
----------------------------------------
| 2  | def       | 2     | desc        |
----------------------------------------
| 3  | ghi       | 1     | desc        |
----------------------------------------
| .  | ......... | .     | desc        |
----------------------------------------
| 9  | mno       | 8     | desc        |
----------------------------------------

控制器

$postArray = Post::with('postAdvancedOptions')->where('id', '=', $id)->get()->toArray();

结果我当前的输出看起来像这样

array(3) [
array(15) [
    'id' => integer 64
    'title' => string (19) "test"
    'content' => string (6) "lorem ipsum"        
    'post_advanced_options' => array(3) [
        array(4) [
            'id' => integer 34
            'post_id' => integer 64
            'advanced_option_id' => integer 1
            'option' => string (3) "xxx"
        ]
        array(4) [
            'id' => integer 35
            'post_id' => integer 64
            'advanced_option_id' => integer 1
            'option' => string (3) "yyy"
        ]
        array(4) [
            'id' => integer 36
            'post_id' => integer 64
            'advanced_option_id' => integer 6
            'option' => string (3) "vvv"
        ]
    ]
]

但我需要的是：

array(3) [
array(15) [
    'id' => integer 64
    'title' => string (19) "test"
    'content' => string (6) "lorem ipsum"        
    'post_advanced_options' => array(3) [
        array(4) [
            'id' => integer 34
            'post_id' => integer 64
            'advanced_option_id' => integer 1
            'option' => string (3) "xxx"

            'name' => string (3) "asd"
            'description' => string (3) "asdasd"
            'sort' => integer 0

        ]
        array(4) [
            'id' => integer 35
            'post_id' => integer 64
            'advanced_option_id' => integer 1
            'option' => string (3) "yyy"

            'name' => string (3) "asd"
            'description' => string (3) "asdasd"
            'sort' => integer 1

        ]
        array(4) [
            'id' => integer 36
            'post_id' => integer 64
            'advanced_option_id' => integer 6
            'option' => string (3) "vvv"

            'name' => string (3) "asd"
            'description' => string (3) "asdasd"
            'sort' => integer 1
        ]
    ]
]

如何使用 PostAdvancedOptions 和 AdvancedOption

调用发布的关系

..并按 AdvancedOption.sort

订购post_advanced_options

Answer 1

目前，您已将表设置为“多对多”关系，但您的模型未正确设置为具有“多对多”关系。你需要这样的东西：

class Post extends Eloquent {
   public function options() {
      return $this->belongsToMany('AdvancedOption');
   }
}

class AdvancedOption extends Eloquent {
   public function posts() {
      return $this->belongsToMany('Post');
   }
}

您不需要PostAdvancedOptions的模型，因为这是您的数据透视表，不是模型，只是连接关系。每当你告诉Laravel模型belongsToMany时它会自动查找某个数据透视表。该数据透视表将为advanced_option_post，其列数为id，advanced_option_id和post_id。如果你需要，你也可以覆盖它，以便命名别的东西。

您可以阅读有关“多对多”关系的更多信息here。

Answer 2

我对Laravel也相对较新，但如果您只需要AdvancedOptions信息，则可以使用＆＃34; Has Many Through＆＃34;在你的帖子模型中：

class Post extends Eloquent {
    public function AdvancedOptions() {
        return $this->hasManyThrough('PostAdvancedOption', 'AdvancedOption');
    }
}

或者如果你想实现Ross Edman所提到的数据透视表，那么你应该移动＆＃34;值＆＃34;从PostAdvancedOption表到AdvancedOption

Answer 3

如果关系是一对多，则可以将外键保留在子表中（在这种情况下，AdvanceOptions保存Post主键）。

由于您定义了这样的关系，我建议修复数据库模式，AdvanceOption保存了父Post主键，如下所示：

Post Table
------------------------------  
| id | title | content | ... |
------------------------------
| 1  | AAAAA | aaaaaaa | ... |
------------------------------



AdvancedOption Table 
-------------------------------------------------------------------
| id | name      | post_id | value | another advanceoption column |
-------------------------------------------------------------------
| 1  | abc       | 0       |       |                              |
-------------------------------------------------------------------

然后模型看起来像这样：

class Post extends Eloquent {
   public function advanceoption() {
      return $this->hasMany('App\AdvanceOption','post_id');
   }
}

class AdvancedOption extends Eloquent {
   public function post() {
      return $this->belongsTo('App\Post','post_id');
   }
}

最后，找到你想要的结果：

$postArray = Post::find($id)->advanceoption()->get();

Laravel多重关系

3 个答案: