Insert multiple rows in one operation by cloning a queryset with only one column change in Django

Question

I have seen the following link: How do I clone a Django model instance object and save it to the database?

But this one does only 1 object cloning. What if I want to clone multiple objects cloned. For eg. something like this:

foo_objects = Foo.objects.filter(col1=value1)
foo_objects.pk = None
foo_objects.col2=value2
foo_objects.save()

I know I can use bulk insert. Please suggest another method if any.

score 3 · Accepted Answer · answered Feb 22 '14 at 06:51

3

There is no update method on queryset that can update relationship fields. You would have to either use bulk_create() to create/save multiple objects. But before that iterate through queryset to set attributes appropriately.

Something like

foo_objects = Foo.objects.filter(col1=value1)
for f in foo_objects:
    f.pk = None
    f.col2=value2
    f.save() #either do this or save with bulk create as

Foo.objects.bulk_create(foo_objects)

answered Feb 22 '14 at 06:51

Rohan

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This is what I also came up to. I didn't want to create full objects. I have used bulk_create finally. – Anuj Feb 22 '14 at 07:59

score 0 · Answer 2 · answered Feb 22 '14 at 06:51

if you don't want to use bulk create, you can control transaction commit by your own like this

from django.db import transaction

with transaction.commit_on_success():
        for foo_object in foo_objects:
            foo_object.pk = None
            foo_objects.col2=value2
            foo_objects.save()

Insert multiple rows in one operation by cloning a queryset with only one column change in Django

2 Answers2