#23091: Squashed migrations may try to add existing constraint if there was RunPython between create and alter some-model migrations -------------------------------+---------------------- Reporter: anonymous | Owner: nobody Type: Uncategorized | Status: new Component: Migrations | Version: 1.7-rc-1 Severity: Normal | Keywords: Triage Stage: Unreviewed | Has patch: 0 Easy pickings: 0 | UI/UX: 0 -------------------------------+---------------------- I squashed a lot of migrations, some with RunPython functions. The squashed migration needed some fixing to work. At some point of the squashed migration there was a "CreateModel" operation that created some model with relation to User:
{{{ ('user', models.ForeignKey(blank=True, to_field='id', to=settings.AUTH_USER_MODEL, null=True)), }}} But as the models got edited there was a migration (rather pointless, caused by editable=False): {{{ field=models.ForeignKey(blank=True, null=True, to_field='id', to=settings.AUTH_USER_MODEL, editable=False), }}} In between there was a RunPython which quite likely prevented squashing those two migrations into one. Running such migrations ended up with: {{{ File "/var/www/buku/virtualenvs/1405079302/lib/python3.4/site- packages/django/db/backends/utils.py", line 66, in execute return self.cursor.execute(sql, params) django.db.utils.ProgrammingError: constraint "buku_vendor_offerredir_user_id_75e4400f46095260_fk_auth_user_id" for relation "buku_vendor_offerredirect" already exists }}} The SQL it was trying to run was: {{{ ALTER TABLE "buku_vendor_offerredirect" ADD CONSTRAINT buku_vendor_offerredir_user_id_75e4400f46095260_fk_auth_user_id FOREIGN KEY ("user_id") REFERENCES "auth_user" ("id") DEFERRABLE INITIALLY DEFERRED [] }}} It would be handy if that "self.cursor.execute(sql, params)" from django/db/backends/utils.py also printed the SQL it was trying to run so it would be easier to find the operation in migration (or make exception more verbose). I had like 4 such cases. Some quite serious like removing null=True and adding unique=True -- Ticket URL: <https://code.djangoproject.com/ticket/23091> Django <https://code.djangoproject.com/> The Web framework for perfectionists with deadlines. -- You received this message because you are subscribed to the Google Groups "Django updates" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-updates+unsubscr...@googlegroups.com. To post to this group, send email to django-updates@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-updates/052.135420b6e1bb413d924a37b79fb447c5%40djangoproject.com. For more options, visit https://groups.google.com/d/optout.