关键字未传递功能

Question

I am working with django models. I want to pass a model field as a variable. Given my function:

from django.models import models

def updatetable(value, fieldtitle, tablename, uid, refname):  
    workingobj = tablename.objects.get(refname=uid)
    currentvalue = getattr(workingobj, fieldtitle)
    setattr(workingobj, fieldtitle, currentvalue + value)
    workingobj.save()
    return

I have tried:

updatetable(len(sr), 'posts_added', managementmetrics, startdtg, refname=update_dtg_start)

updatetable(len(sr), 'posts_added', managementmetrics, startdtg, refname='update_dtg_start')

and even

updatetable(len(sr), 'posts_added', managementmetrics, startdtg, {refname:update_dtg_start})

I get the error: Cannot resolve keyword 'refname' into field. Choices are: length_of_update, update_dtg_finish, update_dtg_start

I've tried switching out refname for **kwargs but still can't seem to get it to take the field value.

Answer 1

The problem is not in how you call this function: the function itself does not do what you want.

You need to change how you call get . Rather than passing in refname directly, you need to use the dict there :

workingobj = tablename.objects.get(**{refname: uid})

Now you simply call the function in the normal way:

updatetable(len(sr), 'posts_added', managementmetrics, startdtg, 'update_dtg_start')

(You should also consider renaming the tablename parameter: you are not passing a table name, which implies a string, but a model class object.)