How to query a table, in sqlalchemy

Question

I know how to query on a model now. Suppose there is a Question model:

class Question(Base):     __tablename__ = "questions"     id=Column(...)     user_id=Column(...)     ... 

Now, I can do:

question = Session.query(Question).filter_by(user_id=123).one() 

But, now, I have a table (not a model) questions:

questions = Table('questions', Base.metadata,                   Column(id, ...),                   Column(user_id, ...),                   ....) 

How to query it as what I do with models?

Session.query(questions).filter_by(user_id=123).one() 

This will report an error:

Traceback (most recent call last): File "<console>", line 1, in <module> File "E:\Python27\lib\site-packages\sqlalchemy-0.6.3-py2.7.egg\sqlalchemy\orm\query.py", line 851, in filter_by   for key, value in kwargs.iteritems()] File "E:\Python27\lib\site-packages\sqlalchemy-0.6.3-py2.7.egg\sqlalchemy\orm\util.py", line 567, in _entity_descriptor     desc = entity.class_manager[key] AttributeError: 'NoneType' object has no attribute 'class_manager' 

But:

Session.query(questions).all() 

is OK.

Is filter_by only work for models? How can I query on tables?

Answer 1

I think it's Session.query(questions).filter(questions.c.user_id==123).one()

Answer 2

You can query tables that were created with the Table constructor using Session.query(Base.metadata.tables['myTable']).all().