查询django中列表视图的外键表

Question

I am very new to django. I have a django installation and am trying to create a UI in django for a few of the database tables.

In my database there are two tables - Articles and Author. The Articles table has a foreign key to Author table with field name as author_id.

I have managed to create a ListView class that lists articles. The code is like this:

from .models import Article

class ArticleListView(ListView):
    template_name = "article.html"
    context_object_name = 'articles'
    paginate_by = 25

    def get_queryset(self):
        queryset = Article.objects.all().order_by('-created_at')
        return queryset 

Then in the view I loop the Article queryset and prints its fields, and this works fine. However I am not sure how to query the corresponding Author table in order to get the author name and details. Can anyone please help me understand how this can be done? I read a lot of documentation/tutorials about this but I am unable to wrap my head around how to do this. Any help is very much appreciated.

Please note: The Article model was written by earlier django programmer.

Answer 1

If you define a ForeignKey with name column to another model, then Django will construct a database column with the name column_id to obtain the primary key of the related object. But you can use .column to obtain the related object (so not the id , but the corresponding object of that id ).

You can thus change the template, for example to:

<h1>Articles</h1>
<ul>
{% for article in object_list %}
    <li>{{ article.pub_date|date }} - {{ article.headline }}
        </li>
{% empty %}
    <li>No articles yet.</li>
{% endfor %}
</ul>

(given of course an author has a name field).

Since you here will fetch all the author objects, it is usually more efficient to do a prefetch_related(..) on the queryset in that case:

class ArticleListView(ListView):
    template_name = 'article.html'
    paginate_by = 25

    def get_queryset(self):
        return Article.objects..order_by('-created_at')

You can thus call .author on any Article instance to obtain the Author object that relates to it (and for instance fetch properties of that author, modify the author, etc.).