CODEWITHSUNDEEP
pythondjangodjango-viewsdjango-ormdjango-1.5
maazza
maazza

Reputation: 7183

Save a list of objects in django

I am using django 1.5 and i am trying to do something like this :

    quotes = formset.save()
    user = client_form.save()
    for quote in quotes:
        quote.client = user
    quotes.save()

But lists dont have a save() method so is there some built in functionality to do something similar ?

I found this nswer on SO Question about batch save objects in Django

Is it still True with django 1.5 ? Is there no way to avoid the save() call on each object of the list ?

here is my actual view code:

def new_quote(request):
    QuoteLineFormSet = modelformset_factory(QuoteLine, form=QuoteLineForm, extra=2)

    if request.method == 'POST':
        formset = QuoteLineFormSet(request.POST, request.FILES, queryset=QuoteLine.objects.none())
        quote_form = QuoteForm(request.POST, request.FILES)
        if formset.is_valid() and quote_form.is_valid():
            quote_lines = formset.save(commit=False)
            #quote_lines = formset.get_queryset()
            quote = quote_form.save()
            for quote_line in quote_lines:
                quote_line.quote = quote
                quote_line.save()
            request.session['quote_id'] = quote.id
            return HttpResponseRedirect(reverse('new_client'))
    else:
        formset = QuoteLineFormSet(queryset=QuoteLine.objects.none())
        quote_form = QuoteForm()

    return render(request, 'request_quote_form.html', {
        'formset': formset,
        'quote_form': quote_form,
    })

My solution for now

    quote_line_ids = [item.pk for item in formset.save()]
    quote_lines_qs = QuoteLine.objects.filter(pk__in=quote_line_ids)
    quote = quote_form.save()
    quote_lines_qs.update(quote=quote)

Upvotes: 4

Views: 8594

Answers (3)

alecxe
alecxe

Reputation: 473863

You can use update() method on a queryset.

Also see this question and answer: Django: form that updates X amount of models

Upvotes: 5

Akshar Raaj
Akshar Raaj

Reputation: 15211

When you do formset.save(), it hits database as many times as number of forms in the formset. So, its n hits if the number of element in the formset is n.

So, you can have commit=False on the formset which will not hit the db at all. Then you can update the objects and call save() on each object. So, your database calls remain n times.

#doesn't hit the database at all
quotes = formset.save(commit=False)
user = client_form.save()
for quote in quotes:
    quote.client = user
    #hits the db
    quote.save()

Not sure if you can do this entire operation in one call to db.

Upvotes: 2

LarsVegas
LarsVegas

Reputation: 6812

Also have look at this link. Very straightforward easy-to-use approach. From the blog:

for x in seq:
   o = SomeObject()
   o.foo = x
   o.save()

becomes

l = []
for x in seq:
    o = SomeObject()
    o.foo = x
    l.append(o)
insert_many(l)

Upvotes: 0

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