Kulay

function getVectorLength()
{
        print (sqrt(pow($this->x, 2) + pow($this->y, 2)));
}

public function getArticles()
{
return $this->hasMany(Article::className(), ['id' => 'article_id'])
->viaTable('article_tag', ['tag_id' => 'id']);
}

Card::find()
  ->leftJoin('card_tags t1', 't1.card_id = card.id')
  ->leftJoin('card_tags t2', 't2.card_id = card.id')
  ->where([
    'and',
    ['t1.tags_id' => 1],
    ['t2.tags_id' => 2]
  ]);