# How to create records that links to each other? **URL:** \ **Category:** Design\ **Created:** [August 11, 2014, 9:32pm UTC](https://discuss.emberjs.com/t/how-to-create-records-that-links-to-each-other/6057 "2014-08-11T21:32:10Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![gghh](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/gghh/32/15312_2.png) [@gghh](https://discuss.emberjs.com/u/gghh)\ **Post date:** [August 11, 2014, 9:32pm UTC](https://discuss.emberjs.com/t/how-to-create-records-that-links-to-each-other/6057/1 "2014-08-11T21:32:11Z")
hi, in a web forum a `thread` has a `title` plus a bunch of `post`s. A `post` has a `content` and belongs to a `thread`. Like this: ``` App.Thread = DS.Model.extend({ title: DS.attr('string'), posts: DS.hasMany('post', {async: true}) }); App.Post = DS.Model.extend({ content: DS.attr('string'), thread: DS.belongsTo('thread', {async: true}) }); ``` Alice goes to the forum and starts a new `thread`; she is presented with two input boxes, one for the `title` (of her `thread`) and one for the `content` (of the first `post` of the `thread`). When she’s happy, she hits the “post!” button for her thread to go live. On the background, the ember squirrel has some work to do (in the `save` action of the `NewThread` route): 1. create a `thread` record 2. create a `post` record 3. assign the newly created `post` record to the `hasMany` relationship of the `thread` record 4. assign the newly created `thread` record to the `belongsTo` relationship of the `post` record 5. save the `thread` record, sending it over the wire to the datastore in the backend 6. save the `post` record as well. My question is: how to code this list of steps in the `save` action? Though I feel I have a fair understanding of what needs to be done, I fail to see how ember wants this to be coded without fighting the framework. ---
**Author:** ![franip](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/franip/32/15327_2.png) [@franip](https://discuss.emberjs.com/u/franip)\ **Post date:** [August 13, 2014, 11:27am UTC](https://discuss.emberjs.com/t/how-to-create-records-that-links-to-each-other/6057/2 "2014-08-13T11:27:33Z")
I think the order is: 1. Create a `thread` record 2. Create a `post` record 3. Save the `thread` record so now you have the `id` assigned by the server 4. Assign the `thread` record to the `belongsTo` relationship of the `post` record 5. Save the `post` record so now you have the `id` assigned by the backend 6. Assign the `post` record to the `hasMany` relationship of the `thread` record Here is some code: ``` ... save: function() { // create the records var thread = this.store.createRecord('thread', { title: this.get('tittle') }); var post = this.store.createRecord('post', { content: this.get('content') }); var _this = this; // save the thread thread.save().then(function() { // now thread has the id post.set('thread', thread); // save the post post.save().then(function() { // the hasMany relationship is defined as `async: true` so you // have to use `.then()` to access it because `thread.get('posts')` // returns a promise thread.get('posts').then(function(posts) { // add the post to the thread.posts relationship posts.pushObject(post); // I think the following line is not necessary because // thread.posts property is not saved on the server. If you do // a this.store.find('thread', ...) to find this thread you get // the posts filled with the saved posts that belong to it thread.save(); // finally you can transition or do anything you want after the process _this.transitionToRoute('thread.view', thread); // or whatever... }); }); }); } ... ``` I’m new to Ember so I don’t know if this code or aproach is correct so any correction is welcome. PS: sorry my english ---
**Author:** ![gghh](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/gghh/32/15312_2.png) [@gghh](https://discuss.emberjs.com/u/gghh)\ **Post date:** [August 16, 2014, 10:50am UTC](https://discuss.emberjs.com/t/how-to-create-records-that-links-to-each-other/6057/3 "2014-08-16T10:50:46Z")
Thanks a lot franip, that’s really helpful. What I was missing, that you point out in your comments in the code, is that you need your backend on the server to assign an id to an object before you can stick that object as “participating” to whatever relationship. You write: > I think the following line is not necessary because `thread.posts` property is not saved on the server […] can you elaborate on that? Do you mean that relationships only “live” on the client, and are never sent to the server? ---
**Author:** ![franip](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/franip/32/15327_2.png) [@franip](https://discuss.emberjs.com/u/franip)\ **Post date:** [August 18, 2014, 12:00pm UTC](https://discuss.emberjs.com/t/how-to-create-records-that-links-to-each-other/6057/4 "2014-08-18T12:00:36Z")
I think this is not necessary. As you have a thread with many posts you may have a `threads` table and a `posts` table. The `posts` table should have a foreign key named `thread` (or `thread_id`) but you don’t have a `posts` key in the threads table. This is the reason to save the post after creating the thread (so you have the thread’s id) and not need to save the thread after including the post on the hasMany property. As you say this relationship lives on the client and when you make a `this.store.find('thread')` is when you receive from the backend the posts ids that belong to each thread. I don’t know if I have explained it well but I’m on vacancies without a computer and it’s difficult to me to write on the mobile ☹ ---
**Author:** ![gghh](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/gghh/32/15312_2.png) [@gghh](https://discuss.emberjs.com/u/gghh)\ **Post date:** [August 18, 2014, 12:17pm UTC](https://discuss.emberjs.com/t/how-to-create-records-that-links-to-each-other/6057/5 "2014-08-18T12:17:40Z")
that makes sense, thanks.