问为什么我不能在这里尝试获取非对象错误的属性？

EN

var_dump($routine);
echo "aaaaaaaaaaaaaaaaaa";
var_dump($event);

public function index($y, $m, $d) {
    $event = $this->model('Event_model');
    $event = $event->getEventsbydate($y, $m, $d);

    $routine = $this->model('Routine_model'); 
    $routine = $routine->getRoutine($event->routine_id);

    if($event == false){ //if there is nothing in the workout_list

        header("location:/Event/create/$y/$m/$d"); //mylist controller , create method
    } else {
        var_dump($routine);
        echo "aaaaaaaaaaaaaaaaaa";
    var_dump($event);

        //header('location:/Routine/index_bycalendar/$event->routine_id'); 
    }
}

<?php
//for event
public function insert() {
$stmt = $this
    ->_connection
    ->prepare("INSERT INTO event(routine_id, year, month, day) VALUES(:routine_id, :year, :month, :day)");
$stmt->execute(['routine_id' => $this->routine_id, 'year' => $this->year, 'month' => $this->month, 'day' => $this->day]);
return $stmt->rowCount();
}

public function getEventsbydate($year, $month, $day) {
    $stmt = $this
        ->_connection
        ->prepare("SELECT * FROM event WHERE year = :year AND month = :month AND day = :day");
    $stmt->execute(['year' => $year, 'month' => $month, 'day' => $day]);
    $stmt->setFetchMode(PDO::FETCH_CLASS, "Event_model"); //datatype user
    return $stmt->fetchAll();
}

public function getRoutine($routine_id) {
    $stmt = $this
        ->_connection
        ->prepare("SELECT * FROM routine WHERE routine_id = :routine_id");
    $stmt->execute(['routine_id' => $routine_id]);
    $stmt->setFetchMode(PDO::FETCH_CLASS, "Routine_model"); //datatype user
    return $stmt->fetch(); //it should return a user
}