Add multiple class objects from another class

Question

I want to generate multiple country objects with the similar language object without going through the admin UI.

models.py

from django.db import models

class World(models.Model):
    country = models.CharField(max_length=200)
    Language = models.CharField(max_length=200)

class add_countries(models.Model):
    sub_part1 = ['USA','ENGLAND','AUSTRALIA','CANADA']
    for sub in sub_part1:
        sub = World.country
        World.Language = "English"

add_countries()

What exactly is going wrong? I'm guessing you're getting some syntax errors to start with. You could have a look at get_or_create — Kendas
– Kendas, Commented Jun 15, 2018 at 8:57
I am not able to see any errors. Nor am I able to see ['USA','ENGLAND','AUSTRALIA','CANADA'] added — Learning Django
– Learning Django, Commented Jun 15, 2018 at 9:00

navyad · Accepted Answer · 2018-06-15 09:06:37Z

1

    for country in ['USA','ENGLAND','AUSTRALIA','CANADA']:
        World.objects.get_or_create(country=country, language='English')

You can put above code inside a method and call that.

answered Jun 15, 2018 at 9:06

navyad

3,9008 gold badges54 silver badges95 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Learning Django Over a year ago

Thank you so much.

Kendas · Accepted Answer · 2018-06-15 09:10:23Z

If you're looking to have a few database entries that are always there, you should probably consider using data migrations. This would result in these database rows being created when you migrate your database. The basic idea would be something like this:

from django.db import migrations

def add_languages(apps, schema_editor):
    # We can't import the Person model directly as it may be a newer
    # version than this migration expects. We use the historical version.
    World = apps.get_model('yourappname', 'World')
    languages = {'English': ['USA','ENGLAND','AUSTRALIA','CANADA']}
    for language, countries in languages.items():
        for country in countries:
            World.objects.get_or_create(country=country, Language=language)

class Migration(migrations.Migration):

    dependencies = [
        ('yourappname', '0001_initial'),
    ]

    operations = [
        migrations.RunPython(add_languages),
    ]

The migration file would be in your app's migrations directory (something like project_root/yourappname/migrations/0002_insert_languages.py in this case). Consult the documentation for more information.

Collectives™ on Stack Overflow

Add multiple class objects from another class

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related