Hello all, I keep hitting an assertion error, "Dependency Rule Tried To Blank Out Primary Key..." when trying to remove all children using an association object.
My situation seems very similar to https://groups.google.com/forum/#!topic/sqlalchemy/3g4__pFHZTs However, based on Michaels response, it sounds like we must delete both objects, which I don't want to do since it is a many-many relationship. Below is a simple equivalent to my code: Page(Object): page_id = Column(Integer, primary_key = True) title = Column(String) user_relationships = relationship(Page_to_User) User(Object): user_id = Column(Integer, primary_key = True) name = Column(String) Page_to_User(Object): page_id = Column(Integer, ForeignKey(Page.page_id), primary_key = True) user_id = Column(Integer, ForeignKey(User.user_id), primary_key = True) relationship_type = (Integer, ForeignKey(Relationship.type_id), primary_key = True) page = relationship(Page) user = relationship(User) Assuming page1 object has many users tied to it, and I want to unassociate them all... print page1.user_relationships # populated with stuff, works as expected page1.user_relationships = [] session.flush() # error here My understanding is it page1.user_relationships is populated correctly due to the FK set on Page_to_User Association object. Somehow, it's getting the 'tried to blank out' error on the Page_to_User table... In the link above, Michael's write up sounds like the cause is if I try to delete the Page object, which references Page_to_User, which has foreign key to Page. It then tries to set page_id to null on Page_to_Actor due to FK constraints and ultimately fails. However, I'm not trying to delete the Page object here - just the associations to User. The Page stays. The User objects also stay. They just are not linked anymore... Can someone help explain why I still trigger this issue? I can make it go away setting viewonly=True on the user_relationships relationship() call, but I don't want it view only - I want to be able to update and work with those objects as usual. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/groups/opt_out.
