how to write 3 dependant table join query in Django - django

Question

I am new in django , I want to create join query in django, my model is as follow
Model.py
Class area_country(models.Model):
country_id = models.AutoField(primary_key=True)
country_name = models.CharField(max_length=100, null=True)
short_name= models.CharField(max_length=20, null=True)
flag_enable = models.SmallIntegerField()
class Meta:
db_table = "area_country"
class area_state(models.Model):
state_id = models.AutoField(primary_key=True)
state_name = models.CharField(max_length=100, null=True)
short_name = models.CharField(max_length=20, null=True)
country_id = models.ForeignKey(area_country, on_delete=models.CASCADE)
flag_enable = models.SmallIntegerField()
class Meta:
db_table = "area_state"
class area_city(models.Model):
city_id = models.AutoField(primary_key=True)
city_name = models.CharField(max_length=100, null=True)
short_name = models.CharField(max_length=20, null=True)
state_id = models.ForeignKey(area_state, on_delete=models.CASCADE)
flag_enable = models.SmallIntegerField()
class Meta:
db_table = "area_city"
i need query like
SELECT "area_country"."country_id",
"area_country"."country_name",
"area_state"."state_id",
"area_state"."state_name",
"area_city"."city_id",
"area_city"."city_name"
FROM "area_country"
LEFT OUTER JOIN "area_state" ON ("area_country"."country_id" = "area_state"."country_id_id")
LEFT OUTER JOIN "area_city" ON ("area_state"."state_id" = "area_city"."state_id_id")
** Try by me **
view.py
result = area_country.objects.all().select_related('area_state').values('country_id', 'country_name', 'area_state__state_id', 'area_state__state_name')
when i print it by using query = result.query
SELECT "area_country"."country_id", "area_country"."country_name", "area_state"."state_id", "area_state"."state_name"
FROM "area_country"
LEFT OUTER JOIN "area_state" ON ("area_country"."country_id" = "area_state"."country_id_id")
this is ok now i try
result = area_country.objects.all().select_related('area_state').select_related('area_city').values('country_id', 'country_name', 'area_state__state_id', 'area_state__state_name','area_city__city_id','area_city__city_name')
it show me error
Cannot resolve keyword 'area_city' into field. Choices are: area_state, country_id, country_name, flag_enable, short_name
please help me for django query.
for information friends, i know how to write raw query in django with cursor = connection.cursor()

Answer 1

finally solution is,
let me clear . i want array for js datatable thats why temp = [] and also i want json response so JsonResponse,
view.py
class get_all_country_state_city(View):
def get(self, request):
citys = area_city.objects.all()
response = []
if citys:
response = []
for value in citys:
temp = []
temp.append(value.city_name)
temp.append(value.state_id.state_name)
temp.append(value.state_id.country_id.country_name)
response.append(temp)
return JsonResponse({'data': response})
if you want to show directly in template then
view.py
citys = area_city.objects.all()
context = {
'citys':citys
}
return render(request, "area.html", context)
template.html
<table >
<tbody>
{% for value in citys %}
<tr><td>{{value.state_id.country_id.country_name}}</td>
<td>{{value.state_id.state_name}}</td>
<td>{{value.city_name}}</td></tr>
{% endfor %}
</tbody>
</table>