how to have database relationship with the active data. in django - django

Question

i have some active and non active data's in EVENT models and active data has the VISITORS form to fill ..so far i have tried OnetoOne relationship but it didn't succeed ..i am getting both active and non active field in VISITORs model..thank you for your time.
here is models.py
class Event(models.Model):
event_id = models.AutoField
Event_Name = models.CharField(max_length=50)
description = RichTextField()
date_And_time = models.DateTimeField()
location=models.CharField(max_length=50)
slugs = models.SlugField(max_length= 200,default="")
picture = models.ImageField(upload_to='wildlife/picture', default="")
active = models.BooleanField(default=False)
class Meta:
ordering = ["date_And_time"]
def __str__(self):
return self.Event_Name
class Eventvisitor(models.Model):
event = models.OneToOneField(Event, on_delete=models.CASCADE, related_name="eventvistor",default="")
name = models.CharField(max_length=50)
email = models.CharField(max_length=70, default="")
phone = models.CharField(max_length=20,default="")
date = models.DateTimeField(auto_now_add=True)
class Meta:
ordering = ['-date']
def __str__(self):
return self.email

Answer 1

You can limit the choices with limit_choices_to=… [Django-doc]. But likely what you want is a ForeignKey, since otherwise, each Event can have at most one related EventVisitor (a OneToOneField is basically a ForeignKey with a unique=True constraint).
class Eventvisitor(models.Model):
event = models.ForeignKey(
Event,
limit_choices_to={'active': True},
on_delete=models.CASCADE,
related_name='eventvistors'
)
name = models.CharField(max_length=50)
email = models.CharField(max_length=70, default="")
phone = models.CharField(max_length=20,default="")
date = models.DateTimeField(auto_now_add=True)
class Meta:
ordering = ['-date']
def __str__(self):
return self.email
Note that while one can only select Events with active=True, if you later set the .active field to False, items will still link to it, since the relation is not enforced at database level.