找出一个Django查询

Question

One Django ORM newbie question. I have the following models:

class Book(models.Model):
    title = models.CharField(max_length=100,null=True)

class BookQuestions(models.Model):
    video = models.ForeignKey(Book,null=True)

class BookAnswered(models.Model):
    answer = models.ForeignKey(BookQuestions, null=True)
    user = models.ForeignKey(User)

How to get Book objects which questions' the user has answered?

Answer 1

You can do it like this:

BookQuestion.objects.filter(bookanswered__user=request.user)

However you might consider that BookAnswered is basically just the linking table of a many-to-many relationship, and replace it completely with a ManyToManyField on BookQuestion pointing to User, in which case you can do this:

BookQuestion.objects.filter(user=request.user)

Answer 2

哦，找到了：

Book.objects.filter(bookquestions__bookanswered__user=request.user)