Load specific relations in a nested eager loading in laravel

Question

I have the following related tables:

tableA 
  - id 
  - value

tableB 
  - id 
  - tableA_id
  - value

tableC 
  - id 
  - tableB_id
  - value


tableD 
  - id 
  - tableC_id
  - value

I normally use a nested eager loading to get the object of tableaA from tableD, for example:

$table_d = TableD::with('TableC.TableB.TableA')->find($id);

And I get an object like this:

{
    "id": 1,
    "value": "value",
    "tableC_id": 1,
    "tablec": {
                "id": 1,
                "value": "value",
                "tableB_id": 1,
                "tableb": {
                            "id": 1,
                            "value": "value",
                            "tableA_id": 1,
                            "tablea": {
                                        "id": 1,
                                        "value": "value"
                            }
                }
    }
}

What I want to achieve is to obtain only the object of table D, with its object from table A related, without having table C and table B in the final object, something like this:

{
    "id": 1,
    "value": "value",
    "tablea": {
                "id": 1,
                "value": "value"
                }
    }
}

I tried adding this function in the model file of Table D:

public function TableA()
    {
        return $this->belongsTo('App\Models\TableC', 'tableC_id')
                                ->join('tableB','tableC.tableB_id','=','tableB.id')
                                ->join('tableA','tableB.tableA_id','=','tableA.id')
                                ->select('tableA.id', 'tableA.value');
    }

but it does not work because when I do the following query, it returns some good objects and others with tableA = null:

$tables_d = TableD::with('TableA')->get()

Am I doing something wrong or is there another way to achieve what I want?

Answer 1

You may be able to skip a table with this->hasManyThrough() but depending on what you really want as 'future features', you may want to have multiple relations with whatever code you desire according to your needs. QueryScopes aswell.