laravel whereMonth not working in collection - php

Question

I want to initialize a collection that I will get from a table but if I use whereMonth on that collection it says that whereMonth does not exist.
I've used whereHas instead of initializing a collection but this becomes a very long code that could still possibly be reduced to a more efficient one.
$makati = [];
$cebu = [];
$davao = [];
for($x = 1; $x <= 12; $x++){
$makati[$x-1] = student::with('branch', 'program')
->whereHas('branch', function($query){
$query->where('name', '!=', 'Language Only');
})
->whereHas('branch', function($query) {
$query->where('name', 'Makati');
})->whereMonth('date_of_signup', $x)->whereYear('date_of_signup', '2019')->count();
}
This is working perfectly fine, but see that I will do the same code for the arrays $cebu and $davao.
$student = student::with('branch', 'program')->whereYear('date_of_signup', '2019')->get();
$student = $student->where('program.name', '!=', 'Language Only');
$makati = [];
$cebu = [];
$davao = [];
for($x = 1; $x <= 12; $x++){
$makati[$x-1] = $student->whereMonth('date_of_signup', $x);
info($makati);
}
I've tried this one but this is where the whereMonth error occurs.
the first code actually works but I want to make a shorter and efficient code.

Answer 1

$student = student::with('branch', 'program')->whereYear('date_of_signup', '2019');
$student = $student->where('program.name', '!=', 'Language Only');
$makati = [];
$cebu = [];
$davao = [];
for($x = 1; $x <= 12; $x++){
$makati[$x-1] = $student->whereMonth('date_of_signup', $x)->get();
info($makati);
}
Am thinking the whereMonth() method doesn't work on a gotten collection instance but on a query builder instance, so getting the collection makes the method inaccessible. like the code I have copied above, do not get until you are done using all the query builders. I hope this helps.

Answer 2

whereMonth('x', 1) is a shortcut that generates the SQL WHERE MONTH(x)=1 . SQL queries aren't generally mapped to the collection even though there is effort made to match collection methods to query builder methods as much as possible. The workaround is:
$student = student::with('branch', 'program')->whereYear('date_of_signup', '2019')->get();
$student = $student->where('program.name', '!=', 'Language Only');
$makati = [];
$cebu = [];
$davao = [];
for($x = 1; $x <= 12; $x++){
$makati[$x-1] = $student->filter(function ($value) use ($x) {
return $value->date_of_signup->month == $x;
});
info($makati);
}
This assumes that date_of_signup is properly casted to a date when retrieved using the $dates property in the model.
This is done in your student model:
class student extends Model {
protected $casts = [ 'date_of_signup' => 'date' ];
// rest of model
}
As a sidenote, it's probably more efficient if you do:
$student = student::with('branch', 'program')
->whereYear('date_of_signup', '2019')
->whereHas('program' => function ($query) {
$query->where('name', '!=', 'Language Only');
})
->get();
which will filter the results using an SQL query instead of getting everything and then filtering on the collection