# How to embed belongsTo relationship in model with custom primaryKeys

**URL:** <https://discuss.emberjs.com/t/how-to-embed-belongsto-relationship-in-model-with-custom-primarykeys/11975>\
**Category:** Ember Data\
**Created:** [November 22, 2016, 3:21am UTC](https://discuss.emberjs.com/t/how-to-embed-belongsto-relationship-in-model-with-custom-primarykeys/11975 "2016-11-22T03:21:35Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![ezy](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/ezy/32/12747_2.png) [@ezy](https://discuss.emberjs.com/u/ezy)\
**Post date:** [November 22, 2016, 3:21am UTC](https://discuss.emberjs.com/t/how-to-embed-belongsto-relationship-in-model-with-custom-primarykeys/11975/1 "2016-11-22T03:21:35Z")

</div>

Im getting the error `Error: Assertion Failed: You need to pass a model name to the store's modelFor method` whilst trying to setup a synchronous embedded data relationship on the model.

My API response data has the following structure:

```javascript
{
  "sites": [
    {
      "site_id": 7382,
      "services": [
        {
          "instance_id": 19118,
          ...
        },
        ...
      }
   ]
}

```

I have the following model, route and serializer files which define a custom primaryKey:

```javascript
// models/site.js
const attr = DS.attr;
const hasMany = DS.hasMany;

export default DS.Model.extend({
  // services: attr(), // this picks up the data if active

  services: DS.hasMany('service', { async: false })
});

// models/service.js
const attr = DS.attr;
const belongsTo = DS.belongsTo;

export default DS.Model.extend({
  site: DS.belongsTo('site')
});

// serializers/site.js
export default ApplicationSerializer.extend({
  primaryKey: 'site_id',
  attrs: {
    services: { embedded: 'always' }
  }
});

// serializers/service.js
export default ApplicationSerializer.extend({
  primaryKey: 'instance_id',
  attrs: {
    site: { embedded: 'always' }
  }
});

// routes/sites/index.js
export default Ember.Route.extend({
  model: function() {
    let superQuery = this._super(...arguments),
        org = superQuery.customer_orgCode;
    return this.store.query('site', {org:org});
  }
});

// routes/services/index.js
export default Ember.Route.extend({
  model: function() {
    return this.store.findAll('service');
  }
});

```

I have a feeling that I need to set a modelFor relationship in the service route, but can’t figure out how to call it on an embedded realtionship.

---

<div class="post-metadata">

**Author:** ![josemarluedke](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/josemarluedke/32/13803_2.png) [@josemarluedke](https://discuss.emberjs.com/u/josemarluedke)\
**Post date:** [November 27, 2016, 9:17pm UTC](https://discuss.emberjs.com/t/how-to-embed-belongsto-relationship-in-model-with-custom-primarykeys/11975/2 "2016-11-27T21:17:02Z")

</div>

Hey @ezy! You need to include the `EmbeddedRecordsMixin` in the serializer to get the embedded belongsTo to work correctly.

So it would look like this:

```nohighlight
//serializers/site.js
import DS from 'ember-data';

export default ApplicationSerializer.extend(DS.EmbeddedRecordsMixin, {
  primaryKey: 'instance_id',
  attrs: {
    site: { embedded: 'always' }
  }
});

```

I hope this can help you.

---

<div class="post-metadata">

**Author:** ![ezy](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/ezy/32/12747_2.png) [@ezy](https://discuss.emberjs.com/u/ezy)\
**Post date:** [November 28, 2016, 10:18pm UTC](https://discuss.emberjs.com/t/how-to-embed-belongsto-relationship-in-model-with-custom-primarykeys/11975/3 "2016-11-28T22:18:24Z")

</div>

Hey, thanks for the response @josemarluedke. I’ve tried this but keep getting an error: `You need to pass a model name to the store's modelFor method`.

Pretty sure this is to do with having a custom `primaryKey` for both `site` and `service` which makes Ember Data bork.