Breddy

class Model extends yii\Db\ActiveRecord {
	public function getPrev() {
		return self::find()->where(['<', 'id', $this->id])->orderBy('id DESC')->one();
	}
	
	public function getNext() {
		return self::find()->where(['>', 'id', $this->id])->orderBy('id ASC')->one();
	}
}