如何使用Django模型在ExtJS网格中获取外键值而不是键？

from django.db import models

class Parent(models.Model):
    name = models.CharField(max_length=100)

class Child(models.Model):
    parent = models.ForeignKey(Parent, on_delete=models.CASCADE)
    name = models.CharField(max_length=100)

from django.http import JsonResponse
from myapp.models import Child

def get_children(request):
    children = Child.objects.select_related('parent').all()
    data = [{'id': child.id, 'name': child.name, 'parent': child.parent.name} for child in children]
    return JsonResponse(data, safe=False)

Ext.define('Child', {
    extend: 'Ext.data.Model',
    fields: [
        {name: 'id', type: 'int'},
        {name: 'name', type: 'string'},
        {name: 'parent', type: 'string', mapping: 'parent.name'}
    ]
});

var store = Ext.create('Ext.data.Store', {
    model: 'Child',
    proxy: {
        type: 'ajax',
        url: '/get_children/',
        reader: {
            type: 'json',
            rootProperty: ''
        }
    },
    autoLoad: true
});

var grid = Ext.create('Ext.grid.Panel', {
    store: store,
    columns: [
        {text: 'ID', dataIndex: 'id'},
        {text: 'Name', dataIndex: 'name'},
        {text: 'Parent', dataIndex: 'parent'}
    ],
    renderTo: Ext.getBody()
});