DatabaseLayout

What are all the objects we're going to store?

• documents
• sentences
• tags (many-many with documents)
• translations (pertain to a sentence, done by a user)
• comments (pertain to a sentence, done by a user)
• users

See https://github.com/hltdi/guampa/blob/master/serverside/model.py for details!

getting foreign keys right

This may help: http://docs.sqlalchemy.org/en/rel_0_8/orm/tutorial.html#building-a-relationship