php - 如何在 Laravel 5 中加入模型？

Question

我有三个表，结构如下(它们在 MySQL 数据库中)连接到我的 Laravel 5 API 和 Eloquent 模型:

# build_sets table
| id | title | description |

# parts table
| id | title | description | color |

# build_set_parts table
| id | build_set_id | part_id | amount | special_info |

目前我做这样的查询:

$buildSets = array();

foreach(BuildSet::with('parts')->get() as $buildSet) {
    $temp = json_decode($buildSet);

    $temp->parts = $buildSet->parts;

    $buildSets[] = $temp;
}

return $buildSets;

我的模型是这样的:

class BuildSet extends Model
{
    protected $table = 'build_sets';
    protected $hidden = ['created_at', 'updated_at'];

    public function parts()
    {
        return $this->hasMany('App\Models\BuildSetPart');
    }
}

class Part extends Model
{
    protected $table = 'parts';
    protected $hidden = ['id', 'created_at', 'updated_at'];

    public function buildSets()
    {
        return $this->hasMany('App\Models\BuildSet');
    }
}

class BuildSetPart extends Model
{
    protected $table = 'build_set_parts';
    protected $hidden = ['id', 'build_set_id', 'part_id', 'created_at', 'updated_at'];

    public function buildSet()
    {
        return $this->belongsTo('App\Models\BuildSet');
    }

    public function part()
    {
        return $this->belongsTo('App\Models\Part');
    }
}

我得到这样的结果(JSON 响应):

[
  {
    "id": 1,
    "title": "Build set 1",
    "description": "This is a small build set.",
    "parts": [
      {
        "amount": 150,
        "special_info": ""
      },
      {
        "amount": 400,
        "special_info": "Extra strong"
      },
      {
        "amount": 25,
        "special_info": ""
      }
    ]
  },
  {
    "id": 2,
    "title": "Build set 2",
    "description": "This is a medium build set.",
    "parts": [
      {
        "amount": 150,
        "special_info": ""
      },
      {
        "amount": 400,
        "special_info": "Extra strong"
      },
      {
        "amount": 25,
        "special_info": ""
      },
      {
        "amount": 25,
        "special_info": ""
      },
      {
        "amount": 25,
        "special_info": ""
      }
    ]
  }
]

如您所见，构建集中包含的“部件”数组中缺少标题、描述和颜色。 所以我的问题是，如何将标题和颜色添加到我的回复中？我可以通过使用 Eloquent 模型来做到这一点，还是我必须自己进行数据库查询，在其中获取所有构建集，然后迭代它们并获取所有部分和构建集部分，然后合并该结果并将其添加到构建集中.

任何人都有一个很好的解决方案，它将给我零件数组中的项目，格式如下:

[
  {
    "title": "Part 1",
    "color": "Red",
    "amount": 25,
    "special_info": ""
  },
  {
    "title": "Part 2",
    "color": "Green",
    "amount": 75,
    "special_info": ""
  }
]

Answer 1

从您的模型中，您得到了 BuildSet 和 Part 之间的多对多关系。

因此，在BuildSet中，可以使用hasManyThrough关系。

模型 BuildSet

public function parts()
{
    return $this->hasManyThrough('App\Models\Part', 'App\Models\BuildSetPart');
}

来源:http://laravel.com/docs/5.0/eloquent#relationships

无论如何，如果你想保持BuildSet和BuildSetPart之间的关系。

我建议您改用它。

public function buildSetPart()
{
   return $this->hasMany('App\Models\BuildSetPart');
}

注意:现在，BuildSet 模型parts() 和buildSetPart() 都得到了

创建关系后，您可以替换代码

$buildSets = array();

foreach(BuildSet::with('parts')->get() as $buildSet) {
    $temp = json_decode($buildSet);

    $temp->parts = $buildSet->parts;

    $buildSets[] = $temp;
}

return $buildSets;

与

return  BuildSet::with('parts')->get();

或者，如果您想要 JSON 格式的输出

return  BuildSet::with('parts')->toJson();

来源:http://laravel.com/docs/5.0/eloquent#collections