How to make a selection from the database (three related tables) in Yii2?

Question

This

There are three tables linked in series.
Action code:

public function actionIndex()
    {
        $model = ForumSection::find()->with('topics.messages')->asArray()->all();
        
        return $this->render('home', ['model' => $model]);
    }

It returns an array like this:

Array
(
    [0] => Array
        (
            [section_id] => 1
            [section_title] => Проекты домов
            [section_title_translit] => proekty-domov
            [view] => 0
            [topics] => Array
                (
                    [0] => Array
                        (
                            [topic_id] => 1
                            [section] => 1
                            [topic_title] => Проект дома Бари
                            [topic_title_translit] => proekt-doma-bari
                            [author] => 0
                            [date] => 
                            [views] => 150
                            [display] => 1
                            [status] => 0
                            [close] => 0
                            [messages] => Array
                                (
                                    [0] => Array
                                        (
                                            [message_id] => 1
                                            [topic] => 1
                                            [author] => 1
                                            [message] => Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
                                            [date] => 22.05.2018 1:15
                                            [likes] => 123
                                            [dislikes] => 23
                                        )

                                    [1] => Array
                                        (
                                            [message_id] => 2
                                            [topic] => 1
                                            [author] => 2
                                            [message] => Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.
                                            [date] => 22.05.2018 2:22
                                            [likes] => 32
                                            [dislikes] => 4
                                        )

                                    [2] => Array
                                        (
                                            [message_id] => 4
                                            [topic] => 1
                                            [author] => 2
                                            [message] => Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.
                                            [date] => 22.05.2018 2:22
                                            [likes] => 32
                                            [dislikes] => 4
                                        )

                                )

                        )
)

...он большой, я его укоротил по понятным причинам. В общем, я это разбираю foreach'ем чтобы были видны принадлежности топиков к разделам. С этим все нормально, но мне нужно, чтобы в каждом массиве topics добавлялось свойство countMessages, в которое записывалось бы количество сообщений, которые находятся в массиве messages, то есть, сами сообщения не нужны на главной странице, поэтому нужно каким-то образом не выводить их, а вместо этого создать свойство в массиве topics с кол-вом сообщений.
Как надо переписать код, чтобы я получил желаемый результат?

Answer 1

I don't understand why you duplicate questions.
And if you want with a method, then like this:

public function getTopicMessagesCount() {
    return $this->getTopicMessages()->count();
}

Where function getTopicMessages is your hasmany getMessages communication method.