model file

model.py

     
class Material(DeclarativeBase):
    __tablename__ = 'materials'

    id = Column(Integer, primary_key=True)
    
    Name = Column(Unicode(50), nullable=False)
    voltage = Column(Float(10), nullable=True)
    vol_1 = Column(Float(10), nullable=True)
    vol_1_ref = Column(Unicode(10), nullable=True)
    vol_2 = Column(Unicode(10), nullable=True)
    vol_2_ref = Column(Unicode(10), nullable=True)
    lookup_vol = Column(Enum('vol_1', 'vol_2',  'Avg_vol', 'min_vol', 'max_vol'))