Actually, just do a query.order_by() is enough. This is specified in the docs although it is a bit hard to find. The docs say: If you don’t want any ordering to be applied to a query, not even the default ordering, call order_by() with no parameters. Here is the implementation of order_by, for your reference … Read more
You need to create an empty migration file and Do your stuff in operations block, as explained in docs. Data Migrations As well as changing the database schema, you can also use migrations to change the data in the database itself, in conjunction with the schema if you want. Now, all you need to do … Read more
Inspired by this question try this for MySQL from django.db.models import Count Product.objects.extra(select={‘day’: ‘date( date_created )’}).values(‘day’) \ .annotate(available=Count(‘date_created’))
Well the documentation is very clear about this –fake-initial Allows Django to skip an app’s initial migration if all database tables with the names of all models created by all CreateModel operations in that migration already exist. This option is intended for use when first running migrations against a database that preexisted the use of … Read more
in User.objects.filter(id__in=[1, 5, 34, 567, 229]) print _.query SELECT <fields> FROM “auth_user” WHERE “auth_user”.”id” IN (1, 5, 34, 567, 229)
This is exactly what select_related() does. The only gotcha is that you have to start with the Answer model, rather than Question, but the result is the same: answers = Answer.objects.filter(question_id=1).select_related() Now each answer object has a pre-fetched ‘question’ attribute, and accessing it won’t hit the db again.
The values_list method returns a ValuesListQuerySet. This means it has the advantages of a queryset. For example it is lazy, so you only fetch the first 25 elements from the database when you slice it. To convert it to a list, use list(). all_commenter_ids = PhotoComment.objects.filter(which_photo=which_photo).order_by(‘-id’).values_list(‘submitted_by’, flat=True)[:25] all_commenter_ids = list(all_commenter_ids) You might be able to … Read more
Hmm, I don’t think you want inlines here. You want to be using the Django admin’s filter_horizontal: https://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.filter_horizontal class ProfileAdmin(UserAdmin) filter_horizontal = (‘opetest’,) That will give you the widget that you’re describing, used to add/remove Groups on the User Change page. Ok, based on your edits, updated answer – basically, what we have is a … Read more
If you’re using Django >= 1.6, there’s a BinaryField
You can just do: try: obj = Model.objects.get(**kwargs) except Model.DoesNotExist: obj = Model(**dict((k,v) for (k,v) in kwargs.items() if ‘__’ not in k)) which is pretty much what get_or_create does, sans commit.