How to update multiple fields of a django model instance?

Question

I'm wondering, what is a standard way of updating multiple fields of an instance of a model in django? ... If I have a model with some fields,

Class foomodel(models.Model):     field1 = models.CharField(max_length=10)     field2 = models.CharField(max_length=10)     field3 = models.CharField(max_length=10)     ... 

... and I instantiate it with one field given, and then in a separate step I want to provide the rest of the fields, how do I do that by just passing a dictionary or key value params? Possible?

In other words, say I have a dictionary with some data in it that has everything I want to write into an instance of that model. The model instance has been instantiated in a separate step and let's say it hasn't been persisted yet. I can say foo_instance.field1 = my_data_dict['field1'] for each field, but something tells me there should be a way of calling a method on the model instance where I just pass all of the field-value pairs at once and it updates them. Something like foo_instance.update(my_data_dict). I don't see any built-in methods like this, am I missing it or how is this efficiently done?

I have a feeling this is an obvious, RTM kind of question but I just haven't seen it in the docs.

Answer 1

It's tempting to mess with __dict__, but that won't apply to attributes inherited from a parent class.

You can either iterate over the dict to assign to the object:

for (key, value) in my_data_dict.items():     setattr(obj, key, value) obj.save() 

Or you can directly modify it from a queryset (making sure your query set only returns the object you're interested in):

FooModel.objects.filter(whatever="anything").update(**my_data_dict)