Database Model Design With Laravel Eloquent - database

Question

we have a problem to query our database in a meant-to-be fashion:
Tables:
employees <1-n> employee_card_validity <n-1> card <1-n> stamptimes
id id id id
employee_id no card_id
card_id timestamp
valid_from
valid_to
Employee is mapped onto Card via the EmployeeCardValidity Pivot which has additional attributes.
We reuse cards which means that a card has multiple entries in the pivot table. Which card is right is determined by valid_from/valid_to. These attributes are constrained not to overlap. Like that there's always a unique relationship from employee to stamptimes where an Employee can have multiple cards and a card can belong to multiple Employees over time.
Where we fail is to define a custom relationship from Employee to Stamptimes which regards which Stamptimes belong to an Employee. That means when I fetch a Stamptime its timestamp is distinctly assigned to a Card because it's inside its valid_from and valid_to.
But I cannot define an appropriate relation that gives me all Stamptimes for a given Employee. The only thing I have so far is to define a static field in Employee and use that to limit the relationship to only fetch Stamptimes of the given time.
public static $date = '';
public function cardsX() {
return $this->belongsToMany('App\Models\Tempos\Card', 'employee_card_validity',
'employee_id', 'card_id')
->wherePivot('valid_from', '>', self::$date);
}
Then I would say in the Controller:
\App\Models\Tempos\Employee::$date = '2020-01-20 00:00:00';
$ags = DepartmentGroup::with(['departments.employees.cardsX.stamptimes'])
But I cannot do that dynamically depending on the actual query result as you could with sql:
SELECT ecv.card_id, employee_id, valid_from, valid_to, s.timestamp
FROM staff.employee_card_validity ecv
join staff.stamptimes s on s.card_id = ecv.card_id
and s.stamptimes between valid_from and coalesce(valid_to , 'infinity'::timestamp)
where employee_id = ?
So my question is: is that database desing unusual or is an ORM mapper just not capable of describing such relationships. Do I have to fall back to QueryBuilder/SQL in such cases?
Do you suit your database model towards ORM or the other way?

Answer 1

You can try:
DB::query()->selectRaw('*')->from('employee_card_validity')
->join('stamptimes', function($join) {
return $join->on('employee_card_validity.card_id', '=', 'stamptimes.card_id')
->whereRaw('stamptimes.timestamp between employee_card_validity.valid_from and employee_card_validity.valid_to');
})->where('employee_id', ?)->get();
If your Laravel is x > 5.5, you can initiate Model extends the Pivot class I believe, so:
EmployeeCardValidity::join('stamptimes', function($join) {
return $join->on('employee_card_validity.card_id', '=', 'stamptimes.card_id')
->whereRaw('stamptimes.timestamp between employee_card_validity.valid_from and employee_card_validity.valid_to');
})->where('employee_id', ?)->get();
But code above is only translating your sql query, I believe I can write better if I know exactly your use cases.