# HABTM - how to insert join row when associated rows exist **URL:** \ **Category:** Rails\ **Created:** [April 29, 2006, 8:26pm UTC](https://www.ruby-forum.com/t/habtm-how-to-insert-join-row-when-associated-rows-exist/59170 "2006-04-29T20:26:32Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Lindsay\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ecae2f/32.png) [@Lindsay\_B](https://www.ruby-forum.com/u/Lindsay_B)\ **Post date:** [April 29, 2006, 8:26pm UTC](https://www.ruby-forum.com/t/habtm-how-to-insert-join-row-when-associated-rows-exist/59170/1 "2006-04-29T20:26:32Z")
I have successfully used HABTM to create a many-to-one-to-many set of rows in one step. Now, if two objects I want to associate already exist, how do I create the join row? The Agile book mentions the ‘push\_with\_attributes’ method. The text says this method is useful for adding additional attributes to the join row (in the example a ‘read\_at’ timestamp). I only require a simple two-key join row - is ‘push\_with\_attributes’ the way to go? -Lindsay ---
**Author:** ![Lindsay\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ecae2f/32.png) [@Lindsay\_B](https://www.ruby-forum.com/u/Lindsay_B)\ **Post date:** [April 29, 2006, 8:30pm UTC](https://www.ruby-forum.com/t/habtm-how-to-insert-join-row-when-associated-rows-exist/59170/2 "2006-04-29T20:30:48Z")
Lindsay B. wrote: > many-to-one-to-many set of rows should read ’ one-to-many-to-one rows’ -Lindsay ---
**Author:** ![Lindsay\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ecae2f/32.png) [@Lindsay\_B](https://www.ruby-forum.com/u/Lindsay_B)\ **Post date:** [April 29, 2006, 10:02pm UTC](https://www.ruby-forum.com/t/habtm-how-to-insert-join-row-when-associated-rows-exist/59170/3 "2006-04-29T22:02:10Z")
It’s OK, I figured it out. -Lindsay ---
**Author:** ![Lindsay\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ecae2f/32.png) [@Lindsay\_B](https://www.ruby-forum.com/u/Lindsay_B)\ **Post date:** [April 30, 2006, 3:54pm UTC](https://www.ruby-forum.com/t/habtm-how-to-insert-join-row-when-associated-rows-exist/59170/4 "2006-04-30T15:54:25Z")
> Please end your monolog in a proper way by stating your solution. A bug in my model’s validation prevented the join row from being created. No solution as such. - Lindsay ---
**Author:** ![Lindsay\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ecae2f/32.png) [@Lindsay\_B](https://www.ruby-forum.com/u/Lindsay_B)\ **Post date:** [May 3, 2006, 7:09pm UTC](https://www.ruby-forum.com/t/habtm-how-to-insert-join-row-when-associated-rows-exist/59170/5 "2006-05-03T19:09:39Z")
push with attributes is not what you want to use. that’s for when you have additional columns in your join table other than the two id columns for the joined tables. example of what you want to do: assumiing a habtm between foo and bar (using table bars\_foos as join tabled) foo = Foo.find(1) bar = Bar.find(1) foo.bars \<\< bar # or you could do bar.foos \<\< foo, same results this will create the association in the join table. > **[ActiveRecord::Associations::ClassMethods](https://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#M000533)** > > Associations are a set of macro-like class methods for tying objects together through foreign keys. Chris ---
**Author:** ![Lindsay\_B](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ecae2f/32.png) [@Lindsay\_B](https://www.ruby-forum.com/u/Lindsay_B)\ **Post date:** [April 30, 2006, 11:41am UTC](https://www.ruby-forum.com/t/habtm-how-to-insert-join-row-when-associated-rows-exist/59170/6 "2006-04-30T11:41:58Z")
Lindsay B. wrote: > It’s OK, I figured it out. > > -Lindsay Please end your monolog in a proper way by stating your solution.