[Sqlalchemy-tickets] Issue #3838: Class with automap should override all columns? (zzzeek/sqlalchemy)

[Giorgos P. <iss...@bi...>]

New issue 3838: Class with automap should override all columns?
https://bitbucket.org/zzzeek/sqlalchemy/issues/3838/class-with-automap-should-override-all

Giorgos Papadrosou:

Hi,

I have this example:

```
#!python
class CarrierGroup(MyBase):
    __tablename__ = 'carrier_group'
    group_id = Column(Integer, Sequence('carrier_group_group_id_seq'), primary_key=True)
    # group_name = Column(String)  # commented but exists in DB
 
engine = create_engine('postgresql://...')
metadata = MetaData(bind=engine)
MyBase = automap_base(metadata=metadata)
metadata.reflect(only=exclude_tables)
MyBase.prepare(name_for_scalar_relationship=name_for_scalar_relationship)

Session = scoped_session(sessionmaker())
session = Session()
session.add(CarrierGroup(group_name='testgroup'))
```

This code fails in the last statement with "TypeError: 'group_name' is an invalid keyword argument for CarrierGroup
".
Why? If I want to create a Class, do I need to explicitly write all the fields?

Thank you