Django以Unicode方法反向OneToOneField查找

Question

I have schedule and event models like this.

class Schedule(models.Model):
    jan = models.FloatField(default=2.0)
    feb = models.FloatField(default=2.0)

    def __str__(self):
        return 'Some boring value'

class Event(models.Model):
    name = models.CharField(max_length=20)
    schedule = models.OneToOneField(schedule, null=True, on_delete=models.CASCADE)

    def __str__(self):
        return self.name

In my admin view, I want to add the schedule in an EventAdmin class in a collapsed fashion like this.

class ScheduleAdmin(admin.ModelAdmin):
    fieldsets = [
    ('Schedule', {'fields': ['jan','feb']}),
    ]      

class EventAdmin(admin.ModelAdmin):
    fieldsets = [
    ('Event', {'fields': ['name',]}),
    ('Add schedule', {'fields': ['jan','feb'], 'classes': ['collapse']}),
    ]

So when I add a schedule to an event, I want the schedule str method to return the related Event.name field in the admin form, instead of just 'Some boring value' as it does now.

I also really only want to assign a schedule object once to an Event, instead of the form in admin showing a list of other schedules for other events - I have to disable the add and edit functionality if a schedule is added to an event.

I use admin.TabularInline sometimes, and maybe I should try using this method instead, because it also does not register Schedules in the admin (which I'm not really interested in either) - but this will return the error that 'Schedule has no foreign key to Event' and I have not found a way to solve reverse lookups in the admin yet either.

What would be the correct way to proceed?

Answer 1

So when I add a schedule to an event, I want the schedule str method to return the related Event.name field in the admin form, instead of just 'Some boring value' as it does now.

Add related_name='event' to your models.OneToOneField relation, so you can replace return 'Some boring value' with return self.event.name .

As for:

I also really only want to assign a schedule object once to an Event, instead of the form in admin showing a list of other schedules for other events - I have to disable the add and edit functionality if a schedule is added to an event.

It's not very clear what you want to achieve here.