class database_model:
    def __init__(self, id: int | None = None):
        self.__id = id

    @property
    def id(self) -> int | None:
        return self.__id

    def exists(self) -> bool:
        return self.__id != None

    @id.setter
    def id(self, target: int) -> None:
        if self.exists():
            raise Exception("Database item already exists, can not change id.")

        if type(target) != int:
            raise Exception("Target ID must be Int.")

        if target < 1:
            raise Exception("Target ID must be greater than 1.")

        self.__id = target