how to link pages depending on foreign key using django-CodePudding

I tried to link countries to continents depending on the foreign key "ckey". I tried using filter and .raw but it didn't work. I tried to use it directly on HTML but it said it cannot praise it. I need to know if there is another way of linking pages like "continents -> countries -> cities -> ...." using Django.

models

from django.db import models

# Create your models here.
class Continents(models.Model):
    ckey = models.CharField(max_length=10, primary_key=True)
    continentName = models.CharField(max_length=50)

class country(models.Model):
    countryNum = models.IntegerField(primary_key=True)
    countryName = models.CharField(max_length=15)
    countryBrief= models.TextField(max_length=500)
    currency = models.CharField(max_length=15)
    cost = models.FloatField(max_length=10)
    cultures = models.TextField(max_length=300)
    rulesBrief = models.TextField(max_length=200)
    location = models.TextField(max_length=500)
    ckey = models.ForeignKey('Continents', on_delete=models.PROTECT)

views.py

from django.shortcuts import render
from django.http import HttpResponse
from .models import Continents, country

# Create your views here.
def home(request):
    return render(request,"guide/home.html")

def continents(request):
    continentdata = Continents.objects.all()
    return render(request,"guide/Continents.html",{'Continents':continentdata})

def countrylist(request):
    countries = country.objects.all()
    first_person = country.objects.filter(ckey='as45914')
    context = {
        "first_person":first_person,
        "countries":countries,
    }
    return render(request,"guide/countrylist.html",context=context)

html code

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    {{first_person}}
</body>
</html>

strange message I got when I run the code

How do I link pages like that? For example "Europe > United kingdom > all cities under UK London ..." using Django. I know how to do it in general, all countries > all cities, but not in that way.

CodePudding user response：

# Get list by Obj
continentObj = Continents.objects.get(ckey='as45914')
countryList = Country.objects.filter(ckey=cObj)

# Get List by Related Attribute
countryList = Country.objects.filter(ckey__ckey='as45914')

edit

@OP pretty much you'd use related Attributes.

Lets say you had three models

class Continents():
    name = charfield

class Country():
    continents = Key(Continents)

class City():
    country = Key(Country)

Now how to get all Cities in Europe

list_Of_Cities = City.objects.filter(country__continents__name='Europe')

CodePudding user response：

for viwes

def countrylist(request):
    list_Of_Cities = country.objects.filter(ckey__ckey='as45914').values('countryName')

    context = {
         "list_Of_Cities":list_Of_Cities
  }
    return render(request,"guide/countrylist.html",context=context)

and in HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>

    {% for i in list_Of_Cities %}
    {{i.countryName}}
    {% endfor %}

</body>
</html>