class MyEnum(enum.Enum):
    one = "szt"
    two = "kg"

class ProductTable(Base):
    __tablename__ = 'product'
    product_id = Column(Integer, primary_key=True)
    product_name = Column(String(30))
    product_quantity = Column(Integer)
    product_type = Column(ENUM(MyEnum))
    category_id = Column(Integer, ForeignKey('category.id'))
    category = relationship("category", back_populates="product")
    product_description = Column(String(255))

class CategoryTable(Base):
    __tablename__ = 'category'
    id = Column(Integer, primary_key=True)
    category_name = Column(String(25))

    product = relationship("Main_Table", back_populates="category", uselist=False)