go-xorm-update

	u := user{}
	has, err := engine.
		Where("id = ?", id).
		Get(&u)
	if err != nil {
		log.Println(err)
		return
	}
	if !has {
		log.Println("Not Found")
		return
	}
  
	u.FirstName = "太郎更新"
	u.LastName = "テスト更新"
	u.FirstNameKana = "タロウコウシン"
	affected, err = engine.
		Where("id = ?", id).
		Update(&u)
	if err != nil {
		log.Println(err)
		return
	}
	if affected == 0 {
		log.Println("Not Found")
		return
	}