How to dynamically set foreign key in a eloquent model laravel and how to use it with withCount

Question

i have a column name in a table like below

Table Code 1

34222X234X4422	34222X234X4423	34222X234X4424
A1	A15	A15
A1	A6	A7
A3	A3	A3
A3	A3	A7
A5	A15	A8

Table Code 2

ID	cid	Code	Desc
1	4422	A1	desc 1
2	4423	A2	desc 2
3	4422	A3	desc 3
4	4424	A4	desc 4

and so on

I want to count how many record from table Code 2 are exist in table Code 1 column 34222X234X4422, 34222X234X4423, 34222X234X4424 depend on Code_2.cid using Eloquent Laravel withCount.

I am thinking of using Model Relation one-to-many, but the foreign key cannot be static. Is it possible to passing parameter from controller to model relationship and how to input it in the withCount?

I am trying this:

class Code_2 extends Model
{
public function unit($id)
    {
        return $this->hasMany(Code_1::class, $id, 'code);
    }
}

here is my controller

$column = '34222X234X4424';
$detail1 = Code_2::withCount(['unit => function(Builder $query) use ($column){
            $query->on('code_1.'.$column, '=', 'code_2.code');
        },])->get(['id', 'code', 'decs']);

Turn out to be error "Too few arguments to function App\Models\Code_2::unit()".

How can i fix this?

Thank you.

Note: I cannot change the database at all. Just view it only.

Answer 1

You can create a variable in model and pass value for it same as :

Model :

class Code_2 extends Model
{

    protected $table = 'code_2';
    protected $field;
    public function __construct($field = 'code_2_id')
    {
        $this->field = $field;
    }

    public function unit()
    {
        return $this->hasMany(Code_1::class, $this->field, 'Code');
    }
}

And Controller you can use :

$column = '34222X234X4424';
$model = new Code2($column);
$detail1 = $model->withCount('unit')->get(['id', 'code', 'decs']);