class Customer(models.Model): name = models.CharField(max_length=200) # .. class CustomerTicket(models.Model): customer = models.OneToOneField(Customer) date = models.DateTimeField(auto_now_add=True) # .. I want to query all customers. And, adding for each customer its ticket if it has one in the date range - so I will get the ticket object only if it is in the given date range, otherwise the ticket field would be null.
Try this:
from django.db import models customers = Customer.objects.select_related('customerticket').annotate( ticket=models.Case(models.When(models.Q(customerticket__date__gt=date1) & models.Q(customerticket__date__lt=date2), then=models.F('customerticket'))) ) And you will get ticket as a computed field. Note that when referencing relational fields such as ForeignKey or OneToOneField, F() returns the primary key value rather than a model instance, which means your ticket field will have value of the primary key.
Customer.objects.all()?To get customers with related tickets with one query you can use select_related. To make complex condition you can use Q
from django.db.models import Q Customer.objects.select_related('customerticket').filter(Q(customerticket__date__range=["2018-04-11", "2018-04-12"]) | Q(customerticket__isnull=True)) This will filter data by customerticket date.
or condition, see my updates.isnull condition does not seem to workUse queryset.filter:
from django.utils import timezone Customer.objects.exclude(customerticket=None).filter(customerticket__date=timezone.now()) 