How to support reflect with a dict of table names and database views

[gsvitak]

Hello

Thanks for the work. It makes integrating SqlAlchemy into a custom framework a snap.

I have an existing database with some database views. I want to reflect the database to map the tables and the views in a dictionary.

1. How would I support only reflecting a select set of tables?
2. How would I support reflecting views? I noticed the reflect method only support tables in the metadata?

Would I follow the Flask pattern and subclass the Manager class and override the needed methods?

Thanks
Greg

[dgilland]

It looks like SQLAlchemy's reflect() method supports an only argument that can be used to limit the reflection to subset of table names. However, alchy doesn't expose that option in the Manager.reflect() method (but obviously you can subclass it to extend that behavior).

For view, SQLAlchemy has a way to reflect views: http://docs.sqlalchemy.org/en/latest/core/reflection.html#reflecting-views

[gsvitak]

Thanks for the info. Can you please provide an example of how to use the only parameter?

I only have 1 database and when I pass a dictionary to the method of the table names, I get a message stating that the mapping is not available in SQLALCHEMY_BINDS object.

Thanks,
G

[dgilland]

What's your code that produces the error?

[gsvitak]

Thanks for the offer to help.

class Base(ModelBase):
    # extend/override ModelBase if necessary
    pass

Model = make_declarative_base(Base=Base)

config = {
    'SQLALCHEMY_DATABASE_URI': conn_string,
}

reflect_tables = ['people']
db = Manager(config=config, Model=Model)
db.reflect(reflect_tables)

[dgilland]

alchy.Manager.reflect doesn't support the only argument. That's something that's supported in SQLAlchemy's reflect() method but alchy doesn't curry that argument to it unfortunately. So you would need to extend Manager:

• https://github.com/dgilland/alchy/blob/develop/alchy/manager.py#L279
• https://github.com/dgilland/alchy/blob/develop/alchy/manager.py#L249

[gsvitak]

Oh.. stupid on my part.. I misread your previous response. Thanks.

Greg