如何在Django中正确保存FileField实例

from django.db import models

class MyModel(models.Model):
    file = models.FileField(upload_to='files/')

<form method="post" enctype="multipart/form-data">
    {% csrf_token %}
    <input type="file" name="file">
    <input type="submit" value="上传">
</form>

from django.shortcuts import render
from django.http import HttpResponseRedirect
from .models import MyModel

def upload_file(request):
    if request.method == 'POST':
        file = request.FILES['file']
        MyModel.objects.create(file=file)
        return HttpResponseRedirect('/success/')
    return render(request, 'upload.html')

MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
MEDIA_URL = '/media/'

from django.conf.urls import url
from django.conf import settings
from django.conf.urls.static import static
from .views import upload_file

urlpatterns = [
    url(r'^upload/$', upload_file, name='upload'),
] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)