Relation between two models in Django-CodePudding

It seems like a trivial question but I am new to Django. I have two models user and competition.

The user can create and join one or many competition. How to specify this relation as the user can be the owner of competition/s and can be a participant in one or more competition.

CodePudding user response：

I Assume You have two tables User and Competition:

then in competition you can user models.ManyToManyField

Example

class User:
   ...

class Competition:
   ...
   creator = models.ForeignKey(User)
   participents = models.ManyToManyField(User)

CodePudding user response：

To add to the answer above, you may explicitly define the intermediary entity of User and Competition if you would like to customize it. It would look something like this:

class User(models.Model):
   ...
   name = models.CharField(max_length=50)

class Competition(models.Model):
   ...
   creator = models.ForeignKey(User)
   participants = models.ManyToManyField(
      User,
      through="Participants",
      )

class Participants(models.Model):
   TEAM_COLOR_CHOICES = [
      (1,'White'),
      (2, 'Red'),
      (3, 'Blue')
   ]
   user = models.ForeignKey("User", on_delete=models.CASCADE)
   competition = models.ForeignKey("Competition", on_delete=models.CASCADE)
   teamcolor = models.PositiveSmallIntegerField(default=1, choices=TEAM_COLOR_CHOICES )

You can also display attributes within the intermediary and its parents on an HTML template with:

{% for participant in context.participants_set.all %}
{{ participant.user.name }}
{{ participant.teamcolor }}
...
{% endfor %}