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I'm trying to use get_or_create for some fields in my forms, but I'm getting a 500 error when I try to do so.
One of the lines looks like this:
customer.source = Source.objects.get_or_create(name="Website") The error I get for the above code is:
Cannot assign "(<Source: Website>, False)": "Customer.source" must be a "Source" instance. 
481
The trick with the get_or_create method is that it actually returns a tuple of (object, created) . The first element is an instance of the model you are trying to retrieve and the second is a boolean flag to tell if the instance was created or not.
Django get_or_create returns the object that it got and a boolean value that specifies whether the object was created or not. If get_or_create finds multiple objects it will raise a MultipleObjectsReturned exception.
From the documentation get_or_create:
# get_or_create() a person with similar first names. p, created = Person.objects.get_or_create( first_name='John', last_name='Lennon', defaults={'birthday': date(1940, 10, 9)}, ) # get_or_create() didn't have to create an object. >>> created False Explanation: Fields to be evaluated for similarity, have to be mentioned outside defaults. Rest of the fields have to be included in defaults. In case CREATE event occurs, all the fields are taken into consideration.
It looks like you need to be returning into a tuple, instead of a single variable, do like this:
customer.source,created = Source.objects.get_or_create(name="Website") get_or_create returns a tuple.
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