Cannot assign "<QuerySet [<Contact: zak>]>": "Booking.contact" must be a "Contact" instance - django

Question

I have an issue, I created a form where users can make a reservation (in detail view) of a unique product. So one user can have multiples booking. The form used contain email and username. This form is in my detail.html with include variable.
{% include 'store/list.html' with list_title=name %}
So, When I run my server, go to the reservation page, put an username, email and submit, I have an error instead to redirect to an another page.
models.py:
from django.db import models
class Contact(models.Model):
email = models.EmailField(max_length=100)
name = models.CharField(max_length=200)
def __str__(self):
return self.name
class Marque(models.Model):
name = models.CharField(max_length=200, unique=True)
def __str__(self):
return self.name
class Model(models.Model): #Plusieurs models pour une marque
reference = models.IntegerField(null=True)
created_at = models.DateTimeField(auto_now_add=True)
available = models.BooleanField(default=True)
name = models.CharField(max_length=200)
picture = models.URLField()
marque = models.ForeignKey(Marque, on_delete=models.CASCADE)
def __str__(self):
return self.name
class Booking(models.Model): #plusieurs réservation pour un contact
created_at = models.DateTimeField(auto_now_add=True)
contacted = models.BooleanField(default=False)
marque = models.OneToOneField(Marque, on_delete=models.CASCADE)
model = models.OneToOneField(Model, on_delete=models.CASCADE)
contact = models.ForeignKey(Contact, on_delete=models.CASCADE)
def __str__(self):
return self.contact.name
views.py:
...
def detail(request, model_id):
model = get_object_or_404(Model, pk=model_id)
#marques = [marque.name for marque in model.marque.all()]
#marques_name = " ".join(marques)
if request.method == 'POST':
email = request.POST.get('email')
name = request.POST.get('name')
contact = Contact.objects.filter(email=email)
if not contact.exists():
#If a contact is not registered, create a new one
contact = Contact.objects.create(
email = email,
name = name
)
#If no album matches the id, it means the form must have been tweaked
#So returning a 404 is the best solution
model = get_object_or_404(Model, pk=model_id)
booking = Booking.objects.create(
contact = contact,
model = model
)
#Make sure no one can book the model again
model.available = False
model.save()
context = {
'model_name': model.name
}
return render(request, 'store/merci.html', context)
message = "Le model est {}. Conçu par la marque {}".format(model.name, model.marque)
context = {
"model_name" : model.name,
"model_marque" : model.marque,
"model_id": model.id,
"thumbnail" : model.picture
}
return render(request, 'store/detail.html', context)
search_form.html inside of detail.html:
<div class="container">
<div class="col-lg-12 detail-separator">
<form class="col-md-6 col-md-offset-3 text-center" action="{% url 'store:search' %}" method="get" accept-charset="utf-8">
<div class="form-group">
<label for="searchForm">Chercher un Model</label>
<input id="searchForm" class="form-control" name="query">
</div>
<span class="help-block" id="helpBlock">Trouvez le model de voiture de vos rêves !</span>
</form>
</div>
</div>

Answer 1

You contact query returns a queryset:
contact = Contact.objects.filter(email=email)
You then try to use contact as if it were a single Contact object:
booking = Booking.objects.create(
contact = contact,
model = model
)
This is why Django complains that it got a Queryset instead of a Contact.
You need to select one Contact even if the Queryset only contains one single object. E.g.
contacts = Contact.objects.filter(email=email)
if contacts.exists():
contact = contacts[0]
else:
#If a contact is not registered, create a new one
contact = Contact.objects.create(
email = email,
name = name
)
Or, preferably:
try:
contact = Contact.objects.get(email=email)
except DoesNotExist:
contact = Contact.objects.create(
email = email,
name = name
)