Laravel relationships, hasmany and then blongstomany

Question

Hey guys I have a question about multi-relationships.

I have 3 tables:

students - id, username, pass
teachers - id, username, pass
periods - id, teacher_id, name

and student_period for many to many.

that's how the database looks: https://i.imgur.com/MXxLmQj.png

What I'm trying to do is I wanna get all students of teacher via periods, haven't seen such relationship who does that, any idea how to do such thing?

Answer 1

Set the relation between teachers and periods hasMany and belongsTo

Set the relation between students and periods as belongToMany and belongsToMany

then you can get the students of a specific teacher like this

$teacherId = 1;
$students = Student::whereHas('periods.teacher', function($teacherQueryBuilder) use ($teacherId) {
    $teacherQueryBuilder->where('id', $teacherId);
})->get();