Skipping an object if one of the attributes is null in laravel - php

Question

Task: you need to get a students object, with the conditions "group_id*" and "specialty_*id", where all these 3 tables are connected. It is also necessary to paginate only those objects of students for whom a group and specialty was found.
My problem: if the group or specialty data is not found, then the object is still added with the "group: null" attribute to pagination, thereby failing to display the requested number of elements on the page. How can this problem be solved?
The code:
$students = Student::with([
"group" =>
function($query) {
$query->where("id", \request("group_id"));
},
"group.speciality" =>
function($query) {
$query->where("id", \request("speciality_id"));
},
])->paginate(\request("page_size") ? : 10)->toArray();
return response()->json($students);
Preview: when I make a request with parameters
group_id = 2
speciality_id = 2
page_size = 2
The following object is returned:
{
"current_page": 1,
"data": [
{
"id": 1,
"receipt_date": "2010-11-02",
"user": {
"id": 1,
"login": "ykirillova#gmail.com",
"phone": "[phone]",
"role": "user",
"passport": {
"series": 1762,
"number": 384282,
"date_of_issue": "1991-11-27",
"issued": "magni",
"division_code": 3,
"scan": "*photo link*",
"secondname": "Kilikova",
"firstname": "Olga",
"thirdname": "Anisimova",
"birthday": "1973-05-13",
"sex": "W"
}
},
"group": {
"id": 2,
"group_code": "4433",
"speciality": {
"id": 2,
"specialty_title": "Programming in computer systems",
"faculty": "SPO IKTZI"
}
}
},
{
"id": 2,
"receipt_date": "1973-11-07",
"user": {
"id": 2,
"login": "marta.fedorov#dackov.net",
"phone": "[phone]",
"role": "user",
"passport": {
"series": 8241,
"number": 419233,
"date_of_issue": "1980-06-05",
"issued": "quos",
"division_code": 33,
"scan": "*photo link*",
"secondname": "Efremov",
"firstname": "Boleslav",
"thirdname": "Kostin",
"birthday": "2009-04-03",
"sex": "W"
}
},
"group": null
}
],
"per_page": "2",
"total": 75
}
Whereas with group == null, only 2 objects with groups should be returned
{
"current_page": 1,
"data": [
{
"id": 1,
"receipt_date": "2010-11-02",
"user": {
"id": 1,
"login": "ykirillova#gmail.com",
"phone": "[phone]",
"role": "user",
"passport": {
"series": 1762,
"number": 384282,
"date_of_issue": "1991-11-27",
"issued": "magni",
"division_code": 3,
"scan": "*photo link*",
"secondname": "Kilikova",
"firstname": "Olga",
"thirdname": "Anisimova",
"birthday": "1973-05-13",
"sex": "W"
}
},
"group": {
"id": 2,
"group_code": "4433",
"speciality": {
"id": 2,
"specialty_title": "Programming in computer systems",
"faculty": "SPO IKTZI"
}
}
},
{
"id": 5,
"receipt_date": "2002-07-05",
"user": {
"id": 5,
"login": "tester#mail.ru",
"phone": "[phone]",
"role": "user",
"passport": {
"series": 5521,
"number": 866521,
"date_of_issue": "1980-06-05",
"issued": "quos",
"division_code": 33,
"scan": "*photo link*",
"secondname": "Pavlov",
"firstname": "Denis",
"thirdname": "Artemev",
"birthday": "2009-04-03",
"sex": "W"
}
},
"group": {
"id": 2,
"group_code": "4433",
"speciality": {
"id": 2,
"specialty_title": "Programming in computer systems",
"faculty": "SPO IKTZI"
}
}
}
],
"per_page": "2",
"total": 75
}
The data presented is irrelevant as it is randomly generated.
Removing data elements in a loop with group equal to null does not solve the problem, since pagination gets lost.