Retrieving all database objects and its related objects Django - django

Question

I am currently learning Django, and I am finding it a bit difficult wrapping my head around the ManyToMany fields. I am using an intermediate model to manage my relationships.
I have three models; Ticket, User, and TicketUserRelation.
I want to be able to query the ticket model, and retrieve both its corresponding user objects and the ticket object. How would I go about doing this?
In Laravel I would do something along the lines of
Ticket::where('id', '1')->with('contributors')
But I can't really figure out how to do this in Django
The models:
class User(models.Model):
name = models.CharField(max_length=50)
def __str__(self):
return self.name
class Ticket(models.Model):
contributors = models.ManyToManyField(User, through=TicketUserRelation, related_name='tickets')
name = models.CharField(max_length=50)
created_at = models.DateField()
def __str__(self):
return self.name
class TicketUserRelation(models.Model):
id = models.AutoField(primary_key=True, db_column='relation_id')
ticket = models.ForeignKey(Ticket, on_delete=models.CASCADE)
user = models.ForeignKey(User, on_delete=models.CASCADE)
EDIT: I am using an intermediate model so that I can easily add things like join date later.

Answer 1

You don't need the TicketUserRelation model when using Django ORM. You could simply use a ForeignKey in the Ticket model, or use the ManyToManyField already defined, if one ticket can be assigned to multiple users.
class Ticket(models.Model):
# For one user, use ForeignKey
user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='tickets')
# For multiple users, use ManyToManyField
contributors = models.ManyToManyField(User, related_name='tickets')
name = models.CharField(max_length=50)
created_at = models.DateField()
def __str__(self):
return self.name
You can then get all tickets for a user u with:
u.tickets.all()

Answer 2

Figured it out myself, using prefetch_related. I was having trouble understanding how prefetch_related works. For those that are confused too, from my understanding it works like this:
Ticket.objects.all().prefetch_related('contributors')
This returns a queryset, something along the lines of this
<QuerySet [<Ticket: Testing ticket one>, <Ticket: Testing ticket two>, <Ticket: Testing ticket three'>, <Ticket: Testing ticket four>]>
When you then access the elements in the queryset, you can then call .contributors on the object, like so:
# Get the queryset
tickets_with_contribs = Ticket.objects.all().prefetch_related('contributors')
# Print the contributors of the first ticket returned
print(tickets_with_contribs[0].contributors)
# Print the contributors of each ticket
for ticket in tickets_with_contribs:
print(ticket.contributors)
Looking back at it this should have been pretty self explanatory, but oh well.