i'm new with Django and as I read the code, I don't understand the message_set attribute of Django model(called Room):
def room(request, pk):
room = Room.objects.get(id=pk)
**room_messages = room.message_set.all()**
participants = room.participants.all()
portion of Models:
class Room(models.Model):
host = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
topic = models.ForeignKey(Topic, on_delete=models.SET_NULL, null=True)
name = models.CharField(max_length=200)
description = models.TextField(null=True, blank=True)
participants = models.ManyToManyField(
User, related_name='participants', blank=True)
updated = models.DateTimeField(auto_now=True)
created = models.DateTimeField(auto_now_add=True)
class Message(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
room = models.ForeignKey(Room, on_delete=models.CASCADE)
body = models.TextField()
updated = models.DateTimeField(auto_now=True)
created = models.DateTimeField(auto_now_add=True)
If you define a ForeignKey from Message to Room, Django will add a relation in reverse to the from the Room model to its related Messages. By default this relation is named modelname_set with modelname the name of the origin of the model. You can specify another name by overriding the related_name=… parameter [Django-doc].
If you thus access the relation in reverse, you get all Message objects with room as there room, an equivalent query to room.message_set.all() is thus Message.objects.filter(room=room).