On the admin page, how can I show the datetime of an fk-related table?

[timber gyro]

`class Endpoint(models.Model):
server = models.ForeignKey(Server, on_delete=models.CASCADE)
endpoint = models.CharField(max_length=50)

def __str__(self):
    return self.endpoint

class JSON(models.Model):
server = models.ForeignKey(Server, on_delete=models.CASCADE)
check_datetime = models.DateTimeField()
endpoint = models.ForeignKey(Endpoint, on_delete=models.CASCADE)
json = models.JSONField()

def __str__(self):
    return "{}-{}-{}".format(self.server, self.check_datetime, self.endpoint)`

OK, so I have a fairly simple set of models here.

Basically I'm pulling data from someone else's API and saving it (and processing it and displaying it of course)

I would like the admin page to show the datetime on which the JSON was pulled last for each endpoint

It's no problem to do this in a view, but I'm not clear on how I could do this in the admin page itself.

My list_display for Endpoint would be ["server", "endpoint", "last_pulled"] , where last_pulled is the latest check_datetime for this endpoint.

hope that makes sense. A pointer in the right direction would be appreciated.

[timber gyro]

On the admin page, how can I show the datetime of an fk-related table?

[vestal barn]

You probably want to override model admin's queryset, adding annotation to it, and then method that reads it (since before you couldn't read it directly for some reason, iirc)

e.g. example:

@admin.register(models.Platform)
class PlatformAdmin(admin.ModelAdmin):

    ordering = ('priority', )
    list_display = ('name', 'icon', 'priority', 'build_count')

    def build_count(self, obj):
        return obj.build_count

    def get_queryset(self, request):
        qs = super().get_queryset(request)
        qs = qs.annotate(build_count=Count('build'))
        return qs

[timber gyro]

Interesting, I wouldn't have thought of that. I'll give it a try, thank you friend.

[vestal barn]

You can as well just make only a admin or model method, but on list view it might inefficient.

[timber gyro]

I'm not planning on having any regular views for this, just the admin.

[vestal barn]

admin also can be made painfully slow without much effort

But generally both ways are your options

[timber gyro]

Annotate looks perfect.