Paginate with Eloquent but without instantiation Models - laravel

Question

We have two Models:
SimpleModel (id, country, code)
ComplexRelatedModel (id, name, address)
SimpleModel has many ComplexRelatedModel, then
class Product extends Model
{
protected $fillable = [
'name'
];
/* hasOne */
public function complexRelatedChild()
{
return $this->hasOne(self::class, 'parent_id', 'id');
}
}
If we do
$simples = SimpleModel
->with('complexRelatedChild')
->simplePaginate(100000 /* a lot! */);
And we need only do
foreach ($simples as $simple) {
echo $simple->complexRelatedChild->name;
}
Any ComplexChild has hydratated and ready. This takes a lot of memory in my case. And we need just one field without any funciton or feature of Model.
It's possible use some data field from related object or with eloquent this isn't possible?

Answer 1

Not sure I completely understand your question. You want to only load one field from the complexRelatedChild relation to keep memory limit down?
You could do:
$simples = SimpleModel::with(['complexRelatedChild' => function($query){
return $query->select(['id', 'name']);
})
->simplePaginate(100000);
Which can be simplified to:
$simples = SimpleModel::with('complexRelatedChild:id,name')
->simplePaginate(100000);
However if I were you, I would try to paginate less items than 100000.
Update:
You could use chunk or cursor functions to process small batches of SimpleModel and keep memory limit down.
SimpleModel::chunk(200, function ($simples) {
foreach ($simples as $simple) {
}
});
or
foreach (SimpleModel::cursor() as $simple) {
}
See the documentation for more information