'Oracle requires special cases for %% and & operators in query expressions'

def combine_expression(self, connector, sub_expressions):

    if (connector == u'%%'):
        return (u'MOD(%s)' % u','.join(sub_expressions))
    elif (connector == u'&'):
        return (u'BITAND(%s)' % u','.join(sub_expressions))
    elif (connector == u'|'):
        raise NotImplementedError(u'Bit-wise    or    is    not    supported    in    Oracle.')
    return super(DatabaseOperations, self).combine_expression(connector, sub_expressions)
