# Maintaining referental Integrity **URL:** \ **Category:** Rails\ **Created:** [July 22, 2008, 7:43pm UTC](https://www.ruby-forum.com/t/maintaining-referental-integrity/143787 "2008-07-22T19:43:31Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![mitch\_newbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea5d25/32.png) [@mitch\_newbie](https://www.ruby-forum.com/u/mitch_newbie)\ **Post date:** [July 22, 2008, 7:43pm UTC](https://www.ruby-forum.com/t/maintaining-referental-integrity/143787/1 "2008-07-22T19:43:31Z")
If I have two models that are in a one-to-one relationship in Ruby on Rails, and I wish to delete a record. How do I make sure I will delete all the related data from both tables? Is there a simple elegant Ruby way to do this? Thank you for your time in advance, Mitch ---
**Author:** ![mitch\_newbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea5d25/32.png) [@mitch\_newbie](https://www.ruby-forum.com/u/mitch_newbie)\ **Post date:** [July 22, 2008, 9:24pm UTC](https://www.ruby-forum.com/t/maintaining-referental-integrity/143787/2 "2008-07-22T21:24:20Z")
On 22 Jul 2008, at 18:43, Mitchell G. wrote: > If I have two models that are in a one-to-one relationship in Ruby on > Rails, > and I wish to delete a record. > How do I make sure I will delete all the related data from both > tables? > > Is there a simple elegant Ruby way to do this? rails provides the :dependant option. If you want a cast iron guarantee then you need to get the database to do it for you (foreign key) Fred ---
**Author:** ![mitch\_newbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea5d25/32.png) [@mitch\_newbie](https://www.ruby-forum.com/u/mitch_newbie)\ **Post date:** [July 22, 2008, 10:20pm UTC](https://www.ruby-forum.com/t/maintaining-referental-integrity/143787/3 "2008-07-22T22:20:09Z")
Frederick C. wrote: > On 22 Jul 2008, at 18:43, Mitchell G. wrote: > > > If I have two models that are in a one-to-one relationship in Ruby on > > Rails, > > and I wish to delete a record. > > How do I make sure I will delete all the related data from both > > tables? > > > > Is there a simple elegant Ruby way to do this? > > rails provides the :dependant option. > If you want a cast iron guarantee then you need to get the database to > do it for you (foreign key) > > Fred Thanks Fred. I have a foreign key in one of the tables. Does that mean when I delete a record in rails it will automatically delete from both joined tables? Mitch ---
**Author:** ![mitch\_newbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea5d25/32.png) [@mitch\_newbie](https://www.ruby-forum.com/u/mitch_newbie)\ **Post date:** [July 22, 2008, 10:21pm UTC](https://www.ruby-forum.com/t/maintaining-referental-integrity/143787/4 "2008-07-22T22:21:52Z")
On 22 Jul 2008, at 21:20, Mitchell G. wrote: > > > tables? > > > Thanks Fred. I have a foreign key in one of the tables. Does that > > > mean > > > when I delete a record in rails it will automatically delete from both > > > joined tables? By default it will probably just raise an error. Check your database’s documentation Fred ---
**Author:** ![mitch\_newbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea5d25/32.png) [@mitch\_newbie](https://www.ruby-forum.com/u/mitch_newbie)\ **Post date:** [July 22, 2008, 10:38pm UTC](https://www.ruby-forum.com/t/maintaining-referental-integrity/143787/5 "2008-07-22T22:38:52Z")
> > Thanks Fred. I have a foreign key in one of the tables. Does that > > mean > > when I delete a record in rails it will automatically delete from both > > joined tables? > > By default it will probably just raise an error. Check your database’s > documentation Would it depend on whether the belongs\_to on that foreign key relation also has :dependent =\> :destroy? Does the cascading destroy recurse through multiple levels of association or does it only apply to the root object and it’s associations? On Jul 22, 4:21 pm, Frederick C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![mitch\_newbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea5d25/32.png) [@mitch\_newbie](https://www.ruby-forum.com/u/mitch_newbie)\ **Post date:** [July 22, 2008, 11:01pm UTC](https://www.ruby-forum.com/t/maintaining-referental-integrity/143787/6 "2008-07-22T23:01:46Z")
On 22 Jul 2008, at 21:38, Robert W. wrote: > Would it depend on whether the belongs\_to on that foreign key relation > also has :dependent =\> :destroy? > No - the rails world of dependant =\> :destroy and the database world > are independent > Does the cascading destroy recurse > through multiple levels of association or does it only apply to the > root object and it’s associations? Might do - try it and find out 🙂 I would imagine so though. (but :dependent =\> :delete\_all probably doesn’t recurse) Fred