Using Django Models in standalone script - Website not updating

问题

I am trying to update records in my SQLite3 DB using the Django ORM and the update() function.

I can see that after running the update() function in my standalone script, the database has in-fact been updated, but the changes are not reflected on my website until I restart gunicorn with:

sudo systemctl restart gunicorn

I suspect the issue has to do with the way I import my models into my standalone script.

ROOT_DIR = /path/to/root/dir

sys.path.insert(0, ROOT_DIR)
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'AppName .settings')

import django
django.setup()

from main.models import Bet, Investment, Profile
from django.contrib.auth.models import User

Bet.objects.filter(id=4).update(revenue=10)

This bit of code is being run once a day on my server. I would expect to see the updates reflected on my site without having to restart gunicorn.

More context: I am running a create() function in the same standalone script which is updating the database and being reflected on my site as expected without having to restart gunicorn.

回答1:

Maybe this is not a direct answer to your problem, but for a standalone script in Django, I suggest using custom management commands. This way you avoid the setup and environment variables.

For example, you could write a script main/management/commands/my_script_1.py (read the docs about why it goes there):

from django.contrib.auth.models import User
from django.core.management.base import BaseCommand
from main.models import Bet, Investment, Profile

class Command(BaseCommand):
    def handle(self, *args, **options):
        self.stdout.write('Before: {}'.format(
            [(e.pk, e.revenue) for e in Bet.objects.filter(id=4)]))

        # do the update of rows
        Bet.objects.filter(id=4).update(revenue=10)

        self.stdout.write('After: {}'.format(
            [(e.pk, e.revenue) for e in Bet.objects.filter(id=4)]))

And then you can invoke the script like this (in linux):

$ ./manage.py my_script_1

Or, if you have your code inside an virtual env, but want to call your script form a cron job:

$ crontab -l
0 5 * * * cd /path/to/project && /path/to/project/.venv/bin/python /path/to/project/manage.py my_script_1 > /dev/null 2>&1

来源：https://stackoverflow.com/questions/54158666/using-django-models-in-standalone-script-website-not-updating

标签

python

django

sqlite

gunicorn