I found out the cause was that I recently removed the max_documents field in the Template model, Postgres automatically deletes a constraint when one of the related columns is deleted and Django does not realize it. I manually updated the Django migration that deleted the field to also deleted the constrain and it worked fine.
On Fri, Oct 4, 2024, 10:52 Alan Evangelista <[email protected]> wrote: > Hi, everyone. > > I have the following db model: > > class Template(models.Model): > max_documents = models.PositiveIntegerField(default=1) > is_comparison = models.BooleanField(default=False) > ... > class Meta: > constraints = [ > models.CheckConstraint( > check=models.Q(is_comparison=False) | > models.Q(max_documents__gte=2, is_comparison=True), > name="is_comparison_requires_min_documents", > ), > ] > > I recently added this check constraint above and makemigrations created > the following db migration: > > class Migration(migrations.Migration): > dependencies = [ > ... > ] > > operations = [ > migrations.AddConstraint( > model_name="template", > constraint=models.CheckConstraint( > check=models.Q( > ("is_comparison", False), > models.Q(("is_comparison", True), > ("max_documents__gte", 2)), > _connector="OR", > ), > name="is_comparison_requires_min_documents", > ), > ), > ] > > Today I deleted the constraint and ran makemigrations again, which created > this second migration: > > class Migration(migrations.Migration): > dependencies = [ > ... > ] > > operations = [ > migrations.RemoveConstraint( > model_name="template", > name="is_comparison_requires_min_documents", > ), > ] > > When I try to run the 2nd migration, I get the following Postgres error > from Django: > django.db.utils.ProgrammingError: constraint > "is_comparison_requires_min_documents" of relation "ai_template" does not > exist > > I checked the ai_template table schema and confirmed there is no check > constraint there. It seems to me Django didn't create the check constraint > on the Postgres db side (maybe it was enforcing it on its side) and now is > trying to remove it from Postgres. Is that a bug or am I missing something? > > Thanks in advance! > > -- > You received this message because you are subscribed to a topic in the > Google Groups "Django users" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/django-users/VBkLU6AP9b4/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-users/8d16410d-ded2-4f2f-a457-675127825443n%40googlegroups.com > <https://groups.google.com/d/msgid/django-users/8d16410d-ded2-4f2f-a457-675127825443n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAKz%2BTUsu1BE9EzvUxPHfz8ND%2BWL3uA%2B0ZyM9jsWfG%2BektwUt_Q%40mail.gmail.com.
