I am trying to get the latest Django model object but cannot seem to succeed.
Neither of these are working:
obj = Model.objects.filter(testfield=12).latest()
obj = Model.objects.latest().filter(testfield=12)
obj= Model.objects.filter(testfield=12).order_by('-id')[:1]
NewsPostImage.objects.filter(newsPostTarget=img_id).first()
. Hope it helps.
See the docs from django: https://docs.djangoproject.com/en/dev/ref/models/querysets/#latest
You need to specify a field in latest(). eg.
obj= Model.objects.filter(testfield=12).latest('testfield')
Or if your model’s Meta specifies get_latest_by, you can leave off the field_name
argument to earliest() or latest()
. Django will use the field specified in get_latest_by
by default.
obj= Model.objects.filter(testfield=12).order_by('-id')[0]
latest
is really designed to work with date fields (it probably does work with other total-ordered types too, but not sure). And the only way you can use it without specifying the field name is by setting the get_latest_by
meta attribute, as mentioned here.
Model.objects.latest('id')
obj= Model.objects.filter(testfield=12).order_by('-id')[:1]
is the right solution
You can do comparison with this down here.
https://i.stack.imgur.com/49QK0.png
latest('created')
is same as order_by('-created').first()
Please correct me if I am wrong
obj = Model.objects.filter(testfield=12).order_by('id').latest('id')
Filter based on what field you need - in this case is testfield
Model.objects.filter(testfield=12)
In order to get the latest record, first you need to sort the queryset. So that it knows to return the last record based on a criteria.
Now, order the results base on your primary key - most of the times the pk=id
Model.objects.filter(testfield=12).order_by('id')
https://docs.djangoproject.com/en/4.0/ref/models/querysets/#order-by
By default, results returned by a QuerySet are ordered by the ordering tuple given by the ordering option in the model’s Meta. You can override this on a per-QuerySet basis by using the order_by method.
After you have the queryset and you have sorted it. Get the latest based on the criteria you need - in this case is the id.
Model.objects.filter(testfield=12).order_by('id').latest('id')
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