Laravel: hasMany relationship breaks query with where clause - laravel

Question

This is my first Laravel project, so maybe I'm misunderstanding something.
I have Clients and Campaigns contollers, and clients are setup with hasMany campaigns
class Client extends Model
{
public function campaigns(){
return $this->hasMany('App\Campaign');
}
}
in the Clients Show method, this query doesn't work:
$client = Client::find($id);
$campaigns = $client->campaigns
->where(function($query) use($startdate, $enddate) {
$query->wherebetween('start_date', [$startdate, $enddate])
->orwherebetween('end_date', [$startdate, $enddate]);
})
->sortBy('start_date')
->groupBy(function($val) {
return Carbon::parse($val->start_date)->format('F Y');
});
I get the error:
explode() expects parameter 2 to be string, object given
The error page shows a red line on the }) after the orwhereBetween clause.
But this query does work:
$campaigns = DB::table('campaigns')
->where('client_id', $client->id)
->where(function($query) use($startdate, $enddate) {
$query->wherebetween('start_date', [$startdate, $enddate])
->orwherebetween('end_date', [$startdate, $enddate]);
})
->orderBy('start_date')
->get()
->groupBy(function($val) {
return Carbon::parse($val->start_date)->format('F Y');
});
My problem is, the second query doens't let me access $campaign->tasks once I'm on the show view, which I need.
So, does anyone know why the where clause would cause an issue when accessing $client->campaigns but not when using DB?

Answer 1

That's because before you call get method the object is an instance of Eloquent Builder class and the groupBy method doesn't accepts any parameter as a closure. However after calling the get method it changes to an instance of Collection class which has groupBy method as well and it accepts closure.
By the way sortBy doen't belong to Eloquent builder instead you have to use orderBy before executing your query using get method.
Here are the available methods of Collection
https://laravel.com/docs/5.7/collections#available-methods
Try this code out and don't forget to call the methods camel case otherwise it can make you serious problems on deployment.
$dates = $client->campaigns()
->where(function($query) use($startdate, $enddate) {
$query->whereBetween('start_date', [$startdate, $enddate])
->orWhereBetween('end_date', [$startdate, $enddate]);
})
->orderBy('start_date')
->get()
->groupBy(function($val) {
return Carbon::parse($val->start_date)->format('F Y');
});
foreach($dates as $campaigns){
foreach($campaigns as $campaign){
dump($campaign->tasks);
}
}