How to create a model that summary from others model, and not save into database but show in admin page?

Question

I have a problem: I need to create a table in an admin page that summary data from others model but it's not an actual real model in the database.

How to implement this?

Answer 1

I am assuming you are going to use existing models to calculate summery. Create instance methods/ properties in your model(as this will help to calculate your row level summery on models). For admin side you can use ModelAdmin with your Model (Probably a proxy model) and then blocki the actions.

Model instance method/property will used to calculate row level summery

class YourMainModel(models.Model):
    # Your Model code
    def instanceMethod(self)
        return some_summery_calculation_based_on_model_fields

    @property
    def instanceProperty(self)
        return some_summery_calculation_based_on_model_fields

class YourMainModelProxy(YourMainModel)
    class Meta:
        proxy=True

Now in admin.py

class YourSummeryModelAdmin(admin.ModelAdmin):
    #Configure your model admin (Somewhat like this)
    model = YourMainModelProxy
    list_display = ['instanceMethod','instanceProperty'...]

    # Disable add permission 
    def has_add_permission(self, request):
        return False

    # Disable delete permission
    def has_delete_permission(self, request, obj=None):
        return False

I hope this will be help.