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Django calling save on a QuerySet object - 'QuerySet' object has no attribute 'save'

开发者 https://www.devze.com 2023-03-09 22:47 出处:网络
How would I get the below to work? player = Player.objects.get(pk=player_id) game = Game.objects.get(pk=game_开发者_运维知识库id)

How would I get the below to work?

player = Player.objects.get(pk=player_id)
game = Game.objects.get(pk=game_开发者_运维知识库id)
game_participant = GameParticipant.objects.filter(player=player, game=game)
game_participant.save()

I when the object already exists in the datbase then I get:

'QuerySet' object has no attribute 'save'.

In terms of my Models, GameParticipant has ForeignKey to both Game and Player. I understand that filter returns a QuerySet but I'm not sure how to cast that to a GameParticipant or is that not the right thinking?

class Player(models.Model):
    name = models.CharField(max_length=30)
    email = models.EmailField()

class Game(models.Model):
    game_date = models.DateTimeField()
    team = models.ForeignKey(Team)
    description = models.CharField(max_length=100, null=True, blank=True)
    score = models.CharField(max_length=10, null=True, blank=True)

class GameParticipant(models.Model):
    STATUS_CHOICES = (('Y','Yes'),('N','No'),('M','Maybe'))
    status = models.CharField(max_length=10, choices=STATUS_CHOICES)
    game = models.ForeignKey(Game)
    player = models.ForeignKey(Player)

OR IS THERE A BETTER WAY TO DO WHAT IM TRYING TO DO? ie. with a .get() instead of a .filter() but then i run into other issues???


You'll want to use the update method since you're dealing with multiple objects:

https://docs.djangoproject.com/en/2.0/topics/db/queries/#updating-multiple-objects-at-once


filter returns a queryset. A queryset isn't a single object, it's a group of objects so it doesn't make sense to call save() on a queryset. Instead you save each individual object IN the queryset:

game_participants = GameParticipant.objects.filter(player=player, game=game)
for object in game_participants:
    object.save()


It is possible to get this error by assigning not saved object to another object foreign field.

    for project in projects:
        project.day = day
    day.save()

and the right way of this is:

    day.save()
    for project in projects:
        project.day = day


filter return a list and if your want a specific single object from it you need give the index of that object

game_participant = GameParticipant.objects.filter(player=player, game=game)[0]


If you use filter() function then you must loop the data, then use save() function

std = Student.objects.filter(player=player, game=game)
for i in std:
  i.name = "somthing"
  i.save()

If you use the get() function then use the save() function without a loop.

std = Student.objects.get(player=player, game=game)
std.name = "somthing"
std.save()


def Clearlist(request):
    que = Feeds.objects.filter(selected=True)
    for i in que:
        i.selected = False
        i.save()
    return redirect('core:all')

this is a good way to save a into queryset


New in Django 2.2: bulk_update

objs = [
    Entry.objects.create(headline='Entry 1'),
    Entry.objects.create(headline='Entry 2'),
]
objs[0].headline = 'This is entry 1'
objs[1].headline = 'This is entry 2'
Entry.objects.bulk_update(objs, ['headline'])


when you use the queryset maybe it return a list that why u should use

game_participant = GameParticipant.objects.filter(player=player, game=game)[0]

instead of

game_participant = GameParticipant.objects.filter(player=player, game=game)

try this it work for me

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