python - 在外键中使用 Django bulk_create 对象？

Question

我正在阅读 Django bulk_create 及其一些“缺陷”:

"
This has a number of caveats though:

1. The model's save() method will not be called, and the pre_save and post_save signals will not be sent.
2. It does not work with child models in a multi-table inheritance scenario.
3. If the model's primary key is an AutoField it does not retrieve and set the primary key attribute, as save() does.
"

我没完全看懂。因此，如果我有一个对象列表，将其传递给 bulk_create:

objList = [a, b, c,] #none are saved
model.objects.bulk_create(objList)

我还能在外键中使用这些对象吗？

for obj in objList:
    o = otherModel(something='asdfasdf', fkey=obj)
    o.save() # will this be fine given the caveats stated above?

那么foreignKey关系会好吗？另外当它说 2. It does not work with child models in a multi-table inheritance scenarios 时，这意味着任何从另一个模型(抽象或非抽象)继承的模型都不能使用 bulk_create？

Answer 1

尝试手动设置 ID。为防止竞争条件，请确保将函数包装为单个事务。

from django.db import transaction, models

@transaction.commit_on_success
def bulk_create_with_manual_ids(foo_list):
    id_start = (Foo.objects.all().aggregate(models.Max('id'))['id__max'] or 0) + 1
    for i,foo in enumerate(foo_list): foo.id = id_start + i
    return Foo.objects.bulk_create(foo_list)

objList = [Foo(),Foo(),Foo()]
foo_objects = bulk_create_with_manual_ids(objList)
Bar(foo=foo_objects[0]).save()

请注意，此方法不适用于任何具有 serial 字段或其他自动递增的数据库生成键的表。由于 ID 是在 Django 端生成的，因此批量创建不会增加 key 。