Custom Data Provider using foreach yii2 - yii2

Question

I'm trying to create a custom dataProvider made out of Professor's id’s (teachers id’s). My site hosts information about teachers, courses, grades, etc. for schools.
ER model
The user Alumno (student) will see a gridview of it’s professors for each course he’s registered in, so, I’m trying to return that information in a dataProvider.
First, I ask if the user is an Alumno.
Then I search for the Asignaturas the Alumno is registered in.
With that information, I search for the professors that teaches that Cursos, to return it’s id’s as a dataProvider, so I made a foreach cycle.
What I need is an array of Profesores id’s so I can show Profesors’s names in the grid view. The actual code is querying the last Profesor id into the dataProvider.
public function actionIndex()
{
$this->layout = 'main';
$searchModel = new ProfesorSearch();
$dataProvider = $searchModel->search(Yii::$app->request->queryParams);
if(User::isUserAlumno(Yii::$app->user->identity->id)){
$alumno = Alumno::find()->where(['id_usuario' => Yii::$app->user->identity->id])->one();
$asignaturas = Asignatura::find()->where(['id_curso' => $alumno->id_curso])->all();
foreach ($asignaturas as $asignatura){
$dataProvider = new ActiveDataProvider([
'query' => Profesor::find()->where(['id' => $asignatura->id_profesor])
]);
}
}
return $this->render('index', [
'searchModel' => $searchModel,
'dataProvider' => $dataProvider,
]);
}
Any help would be appreciated.

Answer 1

You can use column() to get all id_profesor from query.
$profesorIds = Asignatura::find()->select('id_profesor')->where(['id_curso' => $alumno->id_curso])->column();
$dataProvider = new ActiveDataProvider([
'query' => Profesor::find()->where(['id' => $profesorIds])
]);