if ($this->validate()) {
        $db = new User();
        foreach($db->find()->where(['username' => $this->username])->all() as $key=>$val)
        {
            return Yii::$app->user->login($val, $this->rememberMe ? 3600*24*30 : 0);
        }
        $db->username = $this->username;
        $db->password = sha1($this->password);
        $db->password_hash = sha1($this->password);
        $db->created_at = strtotime(time());
        $db->updated_at = strtotime(time());
        $db->email = $this->username;
        $db->status = 1;
        $db->auth_key = 1;
        $db->password_reset_token = sha1($this->password);
        $db->save();
        return Yii::$app->user->login($db, $this->rememberMe ? 3600*24*30 : 0);
    }

return Yii::$app->user->login($val, $this->rememberMe ? 3600*24*30 : 0);