laravel eloquent query group by last id

Question

Hi I\'m trying to get the last register in DB for each equipment

I got like

id   | id_equip
-----+----------
   1 |    3
   2 |    3
   3 |    3
            


        

Answer 1

A simple way, without join, using max:

$query = DB::table('equip')
    ->select(DB::raw('*, max(id) as id'))
    ->groupBy('id_equip')
    ->orderBy('id', 'asc')
    ->get();

(Assuming, of course, that you can count on your id to be in date order.)

---

You can also do this with Eloquent, using a self-referencing one-to-one relationship. The query takes longer, but it's much more Laravel-like:

Define the relationship in your model:

class myModel extends Eloquent {
    public function latestEquipment()
    {
        return $this->hasOne('myModel', 'id_equip', 'id_equip')->latest();
    }
}

(Note that in this case, we're using latest() so that we don't rely on the order of ids to determine the most recent entry, but rather on the created_at date of each record. This is more accurate.)

To retrieve all the records, with their latest equipment entry:

$latest = myModel::with('latestEquipment')->groupBy('id_equip')->get();
// loop over the results
foreach ($latest as $l) {
    if ($l->equipment) {
        echo('ID: ' . $l->id . 'ID_EQUIP: ' . $l->id->id_equip . '
');
    }
}