As a starter, all the operators mentioned in #39 can be implemented using MongoDB regex operators.
Take a look at djongo/base.py call that inherits from Django's
BaseDatabaseWrapper.
Django operators (eg., exact , contains , etc.) will have to be mapped to
any other keyword (You can decide what keyword you want to map it to, for
now it maps to default SQL keywords of LIKE, REGEXP)
Next, in sql2mongo.py define a new Op class and do the needful.
The branch iexact_support has this implementation partially underway.