Laravel framework eloquent relationship query

[faizanahmed786]

I have created relationship between 4 tables.

This are my models:

User
BusinessInfo
ElectrcityInfo
GasInfo
This are the primery keys that I am using in my tables:

user_id (to get login users data from BusinessInfo)
contract_id (This also exists in BusinessInfo I am use it to get data from the other two tables for specific records)
Now I want to get all login users data from BusinessInfo table and each BusinessInfo row has its own 1 row data from ElectricityInfo and GasInfo.

When I am use contract_id in model its give me relationship result null. When it is on user_id its display only 1 ElectrcityInfo with all records.

Controller

$user = Auth::user();
$business = BusinessInfo::where('user_id', $user->id)->first();
$data = $business->electricity()->paginate(6);

return view('Pages.MySite', ['data' => $data]);
BusinessInfo Model

protected $primaryKey = 'contract_id';
public $table = "business_info";
protected $guarded = [];
public $timestamps = false;

public function electricity()
{
return $this->belongsTo('App\Models\ElectricityInfo', 'contract_id');
}

public function gas()
{
return $this->belongsTo('App\Models\GasInfo', 'contract_id');
}