Time in order by AM and PM

Using Django
1

I have an app that displays records from a database on a web page in date/time order, but when it lists them, it sorts by date and then seems to sort by the first number in the time field (example: 2020-06-20 06:00 PM then 2020-06-20 10:00 AM). Is there a way to get the AM times to appear before the PM times?

2

It depends upon how you’re storing the data in the database and where you’re doing the sort.

If you’re storing the date / time as a datetime field, and using the order_by clause to sort the data in your query, it should work correctly - this shouldn’t be an issue.

That you’re asking about this leads me to believe you’re handling this differently.

3

I am storing the date and time as CharField, because I think I ran into other issues storing them as datetime.

I will update the model to store them appropriately and see if that helps.

Thanks for the response.

4

And now I know why I didn’t use Date and Time fields. Here is my new Model:

class Reservation(models.Model):
name = models.CharField(max_length=200)
date = models.DateField(max_length=100)
time = models.TimeField(max_length=100)

class Meta:
	constraints = [
	models.UniqueConstraint(fields=['date', 'time'], name='unique_dt')]

def __str__(self):
	return self.name + " | " + str(self.date) + " | " + str(self.time)

In my code, I want the date and time to be unique together (someone can’t choose the same date and time as someone else). So when I enter information to save a record, every time I try to save it, I receive an error message that I generate, so that tells me it thinks that date/time combination exists in the database when I know for a fact that it doesn’t. This code works accurately using CharField, but then I run into the AM/PM issue.

5

They shouldn’t be two separate fields. You should have one datetime field, that you then extract the appropriate components as necessary when putting your views together.

6

That makes sense. The only reason I separated them is so a user can pick a date and then pick a time on the same form.

7

That’s fine - they don’t need to be the same field/widget. When building your form, you define two form fields that are populated from the database field when the form is created, and joined together when the form is submitted.

8

That makes sense. I will give that a try. Thanks for the great information and tips.

9

You want this form field: https://docs.djangoproject.com/en/3.0/ref/forms/fields/#django.forms.SplitDateTimeField

1 Like
10

Awesome! Thanks for the information.