insert_parent

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle'
});

application.route.js

import Ember from 'ember';

export default Ember.Route.extend({
  mockData: Ember.on('init', function() {
  	this.store.push({
  data: {
    id: '1',
    type: 'person',
    attributes: {
      firstName: 'Tom',
      lastName: 'Dale'
    },
    relationships: {
      children: {
        data: [
          {
            id: '2',
            type: 'person'
          },
          {
            id: '3',
            type: 'person'
          }
        ]
      }
    }
  },
  included: [
    {
      id: '2',
      type: 'person',
      attributes: {
      	firstName: 'Child 1'
      }
    },
    {
      id: '3',
      type: 'person',
      attributes: {
      	firstName: 'Child 2'
      }
    },
    {
      id: '4',
      type: 'person',
      attributes: {
      	firstName: 'Child 3'
      }
    }
  ]
});
    
    this.store.push({
  data: {
    id: '6',
    type: 'person',
    attributes: {
      firstName: 'qqq',
      lastName: 'www'
    },
    relationships: {
      parent: { data: { id: '1', type: 'person' } }
    }
  }
    });
    
  }),
  model() {
  	return this.store.peekRecord('person', 1);
  }
});

application.template.hbs

<h1>People</h1>
<ol>
{{#with model as |person|}}
	<li>Person: {{person.firstName}} {{person.lastName}} parent:
  {{person.parent.id}}
  <br/>
  Children:
  	<ul>
    	{{#each person.children key='id' as |child|}}
  			<li>{{child.firstName}}</li>
      {{/each}}
    </ul>
  </li>
{{/with}}
</ol>
<br>
<br>

models.person.js

import Model, { attr, belongsTo, hasMany } from '@ember-data/model';
export default Model.extend({
  firstName: attr('string'),
  lastName: attr('string'),

  parent: belongsTo('person', { inverse: 'children'  }),
  children: hasMany('person')
});

twiddle.json

{
  "version": "0.4.10",
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1"
  },
  "addons": {
  	"ember-data": "3.18.0"
  }
}