Laravel Eloquent: How to order results of related models?
To answer the original question, the students
dynamic property can also be accessed as a relationship method.
So you have this to fetch all students:
$students = $school->students;
Now as a relationship method, this is equivalent:
$students = $school->students()->get();
Given this, you can now add in some ordering:
$students = $school->students()->orderBy('students.last_name')->get();
Since eloquent will be performing a join, make sure to include the table name when referencing the column to order by.
You can also add this to your students
method if you want to set a default order that $school->students
will always return. Check out the documentation for hasMany()
to see how this works.
You have a few ways of achieving this:
// when eager loading
$school = School::with(['students' => function ($q) {
$q->orderBy('whateverField', 'asc/desc');
}])->find($schoolId);
// when lazy loading
$school = School::find($schoolId);
$school->load(['students' => function ($q) {
$q->orderBy('whateverField', 'asc/desc');
}]);
// or on the collection
$school = School::find($schoolId);
// asc
$school->students->sortBy('whateverProperty');
// desc
$school->students->sortByDesc('whateverProperty');
// or querying students directly
$students = Student::whereHas('school', function ($q) use ($schoolId) {
$q->where('id', $schoolId);
})->orderBy('whateverField')->get();
you can add orderBy to your relation, so the only thing you need to change is
public function students()
{
return $this->hasMany('Student');
}
to
public function students()
{
return $this->hasMany('Student')->orderBy('id', 'desc');
}