新建模型AreaInfo，生成迁移
class AreaInfo(models.Model):
atitle = models.CharField(max_length=20)
aParent = models.ForeignKey('self', null=True, blank=True)
访问关联对象
上级对象：area.aParent
下级对象：area.areainfo_set.all()
在booktest/views.py中定义视图area
from models import AreaInfo
def area(request):
area = AreaInfo.objects.get(pk=130100)
return render(request, 'booktest/area.html', {'area': area})
定义模板area.html
<html>
<head>
<title>地区</title>
</head>
<body>
当前地区:{{ area.atitle }}
<hr>
上级地区：{{area.aParent.atitle}}
<hr>
下级地区：
<ul>
{% for a in area.areainfo_set.all %}
{{ a.atitle }}
{% endfor %}
</ul>
</body>
</html>
在booktest/urls.py中配置一个新的urlconf
urlpatterns = [
url(r'^area/$', views.area, name='area')
]
