Django ORM queries fail to select new objects

Question

Setup:

• Python script A inserts data to a DB every round 15 minutes
• Python script B queries for the last 5 entries every few minutes

Both use django's ORM, same MySQL DB and the same DB user account (same settings.py file)

The Problem:
B is able to fetch only entries inserted before it was run. As if B is running with a frozen DB, frozen at the moment B first connected to the DB.

How come?
Can I control this behavior in django?

Answer 1

If you're reusing same Manager object, you have to keep in mind it's caching. To deal with that you have to manually update.

This will return same results in every iteration:

while True:
   same_every_time = AClass.objects.all().order_by('-id')[:5]
   sleep(300)

In order to make it work properly you have to add the update:

while True:
   AClass.objects.update()
   updated_results = AClass.objects.all().order_by('-id')[:5]
   sleep(300)