Get last record in a queryset

How can I retrie开发者_开发知识库ve the last record in a certain queryset?

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Django Doc:

latest(field_name=None) returns the latest object in the table, by date, using the field_name provided as the date field.

This example returns the latest Entry in the table, according to the pub_date field:

Entry.objects.latest('pub_date')

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EDIT : You now have to use Entry.objects.latest('pub_date')

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You could simply do something like this, using reverse():

queryset.reverse()[0]

Also, beware this warning from the Django documentation:

... note that reverse() should generally only be called on a QuerySet which has a defined ordering (e.g., when querying against a model which defines a default ordering, or when using order_by()). If no such ordering is defined for a given QuerySet, calling reverse() on it has no real effect (the ordering was undefined prior to calling reverse(), and will remain undefined afterward).

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The simplest way to do it is:

books.objects.all().last()

You also use this to get the first entry like so:

books.objects.all().first()

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To get First object:

ModelName.objects.first()

To get last objects:

ModelName.objects.last()

You can use filter

ModelName.objects.filter(name='simple').first()

This works for me.

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Django >= 1.6

Added QuerySet methods first() and last() which are convenience methods returning the first or last object matching the filters. Returns None if there are no objects matching.

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When the queryset is already exhausted, you may do this to avoid another db hint -

last = queryset[len(queryset) - 1] if queryset else None

Don't use try...except....
Django doesn't throw IndexError in this case.
It throws AssertionError or ProgrammingError(when you run python with -O option)

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You can use Model.objects.last() or Model.objects.first(). If no ordering is defined then the queryset is ordered based on the primary key. If you want ordering behaviour queryset then you can refer to the last two points.

If you are thinking to do this, Model.objects.all().last() to retrieve last and Model.objects.all().first() to retrieve first element in a queryset or using filters without a second thought. Then see some caveats below.

The important part to note here is that if you haven't included any ordering in your model the data can be in any order and you will have a random last or first element which was not expected.

Eg. Let's say you have a model named Model1 which has 2 columns id and item_count with 10 rows having id 1 to 10.[There's no ordering defined]

If you fetch Model.objects.all().last() like this, You can get any element from the list of 10 elements. Yes, It is random as there is no default ordering.

So what can be done?

1. You can define ordering based on any field or fields on your model. It has performance issues as well, Please check that also. Ref: Here
2. OR you can use order_by while fetching. Like this: Model.objects.order_by('item_count').last()

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If using django 1.6 and up, its much easier now as the new api been introduced -

Model.object.earliest()

It will give latest() with reverse direction.

p.s. - I know its old question, I posting as if going forward someone land on this question, they get to know this new feature and not end up using old method.

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In a Django template I had to do something like this to get it to work with a reverse queryset:

thread.forumpost_set.all.last

Hope this helps someone looking around on this topic.

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MyModel.objects.order_by('-id')[:1]

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If you use ids with your models, this is the way to go to get the latest one from a qs.

obj = Foo.objects.latest('id')

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You can try this:

MyModel.objects.order_by('-id')[:1]

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The simplest way, without having to worry about the current ordering, is to convert the QuerySet to a list so that you can use Python's normal negative indexing. Like so:

list(User.objects.all())[-1]