Django default=timezone.now() saves records using

问题:

This issue has been occurring on and off for a few weeks now, and it's unlike any that has come up with my project.

Two of the models that are used have a timestamp field, which is by default set to timezone.now().

This is the sequence that raises error flags:

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• Model one is created at time 7:30 PM

• Model two is created at time 10:00 PM, but in the MySQL database it's stored as 7:30 PM!

Every model that is created has its time stamp saved under 7:30 PM, not the actual time, until a certain duration passes. Then a new time is set and all the following models have that new time... Bizzare

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Some extra details which may help in discovering the issue:

I have a bunch of methods that I use to strip my timezones of their tzinfo's and replace them with UTC.

This is because I'm doing a timezone.now() - creationTime calculation to create a: "model was posted this long ago" feature in the project. However, this really should not be the cause of the problem.

I don't think using datetime.datetime.now() will make any difference either.

Anyway, thanks for the help!

回答1:

Just ran into this last week for a field that had default=date.today(). If you remove the parentheses (in this case, try default=timezone.now) then you're passing a callable to the model and it will be called each time a new instance is saved. With the parentheses, it's only being called once when models.py loads.

回答2:

Just set the parameter auto_now_add like this.

timestamp = models.DateTimeField(auto_now_add=True)

Update:

Please don't use auto_now_add. It is not the recommended way, instead do this:

from django.utils import timezone

timestamp = models.DateTimeField(default=timezone.now)