python - Django Get Latest Entry from Database

Question

I've got 2 questions, but they are related to the same topic.

I know how to retrieve data from a for loop using template tags

{% for status in status %}

    <tr>
        <td>{{ status.status}}</td>
    </tr>

{% endfor %}

However when I want to retrieve a single object i get an error even when i use:

po = Status.objects.latest('id')

and remove the for loop.

I get:

'Status' object is not iterable

My questions are:

1. How can I get the latest entry from the database for a given model?
2. How can I setup my templates tags to allow for just a single record?

Answer 1

You have two different questions here:

1. How do I retrieve the latest object from the database.

You can do this using the latest() queryset operator. By reading the docs you will note that this operator works on date fields, not integers.

Status.objects.latest('date_added') # or date_updated

If you want to do this off the ID you will need to order by ID and select the first result. (this will only work if you are using incrementing primary keys, it will not work with UUID's or randomly generated hashes).

Status.objects.order_by('id')[0]

Side note: I would personally use the date_added / date_updated way of doing this.

2. Iterating over a single object

A single object cannot be iterated over. For this you will need to use a different template. Or, you will need to add the single object into a list.

# note the [] around the query
result = [Status.object.latest('date_added')]

Personally I have a different views for listing single / multiple result. I have a ListView for many result objects and a DetailView for single objects.