Python-сообщество

 def get_next_list(k):
    choices=list(BigTable.objects.all().filter(Q(field1__exact=k) | Q(field2__exact=k)
                ).values_list('field1', 'field2', 'field3',
                )
                )
    choice=[]
    for ch in choices:
        ch=set(ch)   # удалить повторяющиеся члены
	if "" in ch:
            ch.remove("") # удалить пустые члены
        if "ABC" in ch:
            ch.remove("ABC") # удалить какой-то конкретный член
        choice=choice + list(ch)
    choice=set(choice)
    return list(choice)

 choices = ["qwert", ... "ABCDE", ...]

 def update_records_in_bigtable(uid_br_next, choices):
    for k in choices:
        q = BigTable.objects.all().filter(Q(field1__exact=k) | 
            Q(field1__exact=k) | Q(field3__exact=k) & Q(field3=0)
            ).update(uid_nr=uid_nr_next)

 def add_records_to_crossreftable(choices, obj):
    for k in choices:
        try:
	    x = CrossRefTable.objects.create(field1=k, uid_nr_foreign=obj)
        except:
            x = DuplicatesTable.objects.create(field1=k)