如何从django中的多个任意字段表中获取news_id列表？

from your_app.models import Table1, Table2, Table3

news_ids = []
table1_objects = Table1.objects.select_related('table2', 'table3').all()

for obj in table1_objects:
    news_ids.append(obj.news_id)

table2_objects = Table2.objects.select_related('table1', 'table3').all()

for obj in table2_objects:
    news_ids.append(obj.table1.news_id)

table3_objects = Table3.objects.select_related('table1', 'table2').all()

for obj in table3_objects:
    news_ids.append(obj.table1.news_id)