Filter via condition on one relation and eager load another relation records - arrays

Question

I have this code I want to get list users with a role of teacher where each teacher will have one object for the personal detail one object for the school detail
public function index(){
$teachers = User::whereHas('roles' , function($q){$q->where('name','isTeacher');})->get();
foreach($teachers as $teacher){
$teacher_id = $teacher->id;
$teacherinSchool = School_Teachers::where('user_id', $teacher_id)->first();
$teacherinSchool = $teacherinSchool->school_id;
$School = School::where('id', $teacherinSchool)->first();
return response(['teacher'=>$teacher, 'school'=>$School]);
}
}
this is what i got but i am expecting to have more that one teacher but it takes the first teacher in the list and display the objects
output in the postman
i have 5 models involved here User model, Role model, User_Role model, school model and school_teacher model

Answer 1

Few things to point out
You are doing queries within a loop (foreach) not good for performance.
Having return response() within foreach loop hence only 1 Teacher record is available
You are getting just the first record for School_Teachers & School
For what you are trying to do can be done more efficiently as under
public function index()
{
$teachers = User::whereHas('roles', fn($query) => $query->where('name', 'isTeacher'))->get();
$schoolIds = School_Teachers::whereIn('user_id', $teachers->pluck('id')->toArray())->pluck('id')->toArray();
$schools = School::whereIn('id', $schoolIds)->get();
return response()->json(['teachers' => $teachers, 'schools' => $schools]);
}
However that is also not optimal, still can be better
Define a relation on User model to link it to School model via School_Teachers (many-to-many)
Then in a single query you can get User(s) which have role of isTeacher with their School
For eg: Say you have a table school_teachers which has columns for user_id, school_id (kind of pivot table) where each record can be uniquely identified by ['user_id', school_id'] composite key - unique index on database table.
Then you can define direct (many-to-many) relation between User and School
//User model
public function schools()
{
return $this->belongsToMany(School::class, 'school_teachers', 'user_id', 'school_id');
}
//School model
public function teachers()
{
return $this->belongsToMany(User::class, 'school_teachers', 'school_id', 'user_id');
}
In controller you can do
public function index()
{
$teachers = User::with('schools')
->whereHas(
'roles',
fn($query) => $query->where('name', 'isTeacher')
)
->get();
return response()->json(['teachers' => $teachers]);
}
Laravel Docs - Eloquent Relationships - Many-to-Many