Yii2 activeRecord - joins - how to correctly get the results of the selection?

Question

MySQL

Let's say there are 2 tables: user(id, name, pass), and post(id, text, user_id) associated with FOREIGN KEY in the Post model:

public function getUser(){
    return $this->hasOne(User::className(), ['id' => 'user_id']);
}

Further, somewhere we have a request for posts with a join of user-authors: Actually, the question is: How exactly to get the user id from the results of this sample, and how to get the id of the post? (table column name prefixes are not considered, otherwise this question simply would not be asked)
$query = Post::find()->joinWith('user');

Answer 1

Good evening.

$query->id; // id post
$query->user->id; // id user