So I have three models
class Post(....
class Project(....
# have a many to many relationship
class ProjectPost(....
post = ..... # foreignkey
project = .... # foreignkey
The data set I want to select is a list of Post objects given a Project object.
This is what I tried:
posts_list = ProjectPost.objects.filter(project=project_object).select_related("post")
But this returns a list of ProjectPost objects rather than a list of Post objects. What is the correct way of doing this?
You may want to use the ManyToManyField()
https://docs.djangoproject.com/en/dev/topics/db/examples/many_to_many/
You should do it like this:
class Post(models.Model):
pass
class Project(models.Model):
posts = models.ManyToManyField(Post)
And then, if you want to access the Posts of a Project, you can do
project_obj.posts.all()
You can use all the Queryset methods
If you want to access the projects of a posts you can do
post_obj.project_set.all()
Same as before, you can use all the Queryset methods.
If for any reason you want to do it that way, you could do:
post_list = ProjectPost.objects.filter(project=project_object).values('post')
Came across this problem myself recently and this was how I solved it. Would love it if someone could comment on whether my solution is efficient.
project_posts = ProjectPost.objects.filter(project=project_object).select_related("post")
posts_lists = map(lambda post: project.post, project_posts)
Objects in posts_lists are now of the correct type.
