id,summary,reporter,owner,description,type,status,component,version,severity,resolution,keywords,cc,stage,has_patch,needs_docs,needs_tests,needs_better_patch,easy,ui_ux 26892,Add documentation about db_constraint for FK and M2M in Multiple Databases section,Timothée Mazzucotelli,nobody,"Working on a project that uses several databases, I have searched for a long time the best way to have ""fake"" or ""cross-db"" foreign keys between tables that are not on the same database. I was very surprised when I recently heard about the db_constraint attribute in model fields ForeignKey and ManyToManyField, and wondered why I have found so many ugly hacks before this very Django feature. Documentation in the Multiple Databases section was very useful, but it would have been a lot more if db_constraint was mentioned in it. And a link back to Multiple Databases from ForeignKey and ManyToManyField db_constraint in model fields reference would also be great. In don't know when db_constraint appeared but this modification should of course apply to each concerned version of Django (I know 1.8 and following are). https://docs.djangoproject.com/en/1.9/topics/db/multi-db/ https://docs.djangoproject.com/en/1.9/ref/models/fields/#django.db.models.ForeignKey.db_constraint https://docs.djangoproject.com/en/1.9/ref/models/fields/#django.db.models.ManyToManyField.db_constraint",Cleanup/optimization,closed,Documentation,1.9,Normal,invalid,fk m2m db_constraint doc,timothee.mazzucotelli@…,Unreviewed,0,0,0,0,1,0