how to filter based on created an object for froingkey django

Question

i have two models (tables) Ticketing and Cancel

class Ticketing(models.Model):
    a= models.CharField(max_length=40)
    b = models.DecimalField(max_digits=10,decimal_places=2)
    #others

class Cancel(models.Model):
    ticket = models.ForeignKey(Ticketing,on_delete=models.CASCADE,related_name="ticket")
    #others

views.py , i have to make a query to show all active Ticketing

Ticketing.objects.filter()#how to filter all objects which `cancel` not created for

thank you , i know make a boolean field then whenver cancel created BooleanField in Ticketing will be False , but i dont want to use it , is it possible please ?!

score 3 · Accepted Answer · answered Jul 09 '21 at 07:41

3

You can filter active Ticketing instances with lookup isnull.

Ticketing.objects.filter(ticket__isnull=True)

answered Jul 09 '21 at 07:41

Jarno Lahtinen

1,713
17
30

did this solution worked? there is no field called ticket in ticketing @HunarMohammed – umair Jul 09 '21 at 07:45
`tickting` field is in the `Cancel` table – artiest Jul 09 '21 at 07:46
@umair it is reverse connection from Cencel to Ticketing – artiest Jul 09 '21 at 07:47
yes, but you query the Ticketing model here. is there a related_name or something there? – umair Jul 09 '21 at 07:47
take a look at this answer https://stackoverflow.com/questions/17328910/django-what-is-reverse-relationship @umair – artiest Jul 09 '21 at 07:49
2

You can use related_name for the name to use for the relation from the related object back to this one. – Jarno Lahtinen Jul 09 '21 at 07:51

how to filter based on created an object for froingkey django

1 Answers1