ContinuumIO/blaze — pull request #413 by mrocklin (2014-07-17 22:21:04+00:00)
Title: SQL databases match nullability to datashape.Option

We now inspect database columns for the `NOT NULL` attribute and use
that to determine if the analagous datashape should have Options or not

We hook this into the datashape-sqlalchemy converters and use
the database reflection built into SQLAlchemy