'Returns a tuple of data suitable for inclusion in a WhereNode
instance.'

def process(self, lookup_type, value, connection):

    from django.db.models.base import ObjectDoesNotExist
    try:
        if self.field:
            params = self.field.get_db_prep_lookup(lookup_type, value, connection=connection, prepared=True)
            db_type = self.field.db_type(connection=connection)
        else:
            params = Field().get_db_prep_lookup(lookup_type, value, connection=connection, prepared=True)
            db_type = None
    except ObjectDoesNotExist:
        raise EmptyShortCircuit
    return ((self.alias, self.col, db_type), params)
