Yii2: how to order activeRecord relation query by related field?

Question

I want to execute this query:

$topics = ForumTopic::find()
            ->with([                
                'lastPost' => function($query) {
                    $query->select(['id', 'ctime']);
                },
            ])
            ->orderBy('lastPost.ctime DESC')
            ->all();

Relation declared in ForumTopic like this:

public function getLastPost()
{
    return $this->hasOne(ForumPost::className(), ['id' => 'lastPostId']);
}

But my query fails (because yii2 make all queries separate and don't join tables). Is any way to achive my purpose by yii2 activeRecord?

Answer 1

So, just for clarification, the right answer is:

$topics = ForumTopic::find()
            ->alias('t')
            ->select(['t.*','l.ctime lastPostCtime'])
            ->joinWith([
                'lastPost l' => function($query) {
                    $query->select(['l.id', 'l.ctime', 'l.userId', 'l.guestName']);
                },
            ])
            ->orderBy('lastPostCtime DESC')
            ->all();