Django Optimal Way of Getting a List of Model Attributes-CodePudding

Let's say this is my models.py file:

class Paper(models.Model):
  title = models.CharField(max_length=20, null=False, blank=False)


class Author(models.Model):
  user = models.ForeignKey(User, on_delete=models.CASCADE)
  papers = models.ManyToManyField(Paper, null=False, blank=False)

An author can have multiple papers and a paper can have multiple authors. I need to get all the papers titles for a given author.

In my views.py, once I have an author object, I need to get a list with all the titles of his papers. I'm doing this:

user = User.objects.get(username=request.user)
author = Author.objects.get(user=user)
papers = [paper.title for paper in author.papers.all()]

Is there a way in Django to make this query without having to iterate over the author papers? Maybe there is a built-in function or something that I'm missing, any suggestions?

CodePudding user response：

This should be enough

papers_by_author = Author.objects.filter(
    user__username=request.user
    ).values('papers__title')

apart from this if you prefetch_related in your code. you ll have some speed.

 Author.objects.get(user=user).prefetch_related('papers')

CodePudding user response：

Also you can get all papers of certain author for example, to get an author like in your code:

author = Author.objects.get(user=user)

and then to get all the papers of this autor:

author.papers.values_list("title", flat=True)

the result is a list with title values only.

To sum up, values_list() with flat=True is what You need here!