Using multiple conditions in Django's Case When expressions

Question

As per the Django documentation, its possible to use multiple conditions with the When clause.

When(
    registered_on__gt=date(2014, 1, 1),
    registered_on__lt=date(2015, 1, 1),
    then='account_type'
)

However, I am unable to use the same when using the Case clause.

Case(
    When(
        registered_on__gt=date(2014, 1, 1),
        registered_on__lt=date(2015, 1, 1), 
        then='account_type'
    ),
    default='default'
)

I end up getting the following error:

TypeError: __init__() got multiple values for keyword argument 'then'

Is there some way I can achieve this? Am I missing something here?

Answer 1

Maybe Q expression can help. Try this:

Case(
    When(
        Q(registered_on__gt=date(2014, 1, 1)) & Q(registered_on__lt=date(2015, 1, 1)),
        then='account_type'
    ),
    default='default'
)

Answer 2

As I see in the Django docs of Case expression, each When expression in the Case class has its own then parameters, and instead of put all the condition in only one parameter When, I think maybe you should extract into 2 When expressions, with 2 separate then parameters, as below:

    Case(
         When(
            registered_on__gt=date(2014, 1, 1),
            then = 'account_type',
         ),
         When(
            registered_on__lt=date(2015, 1, 1),
            then = 'account_type',
         ),
         default='default'
    )

Hope it helps. If anything else is unclear please let me know. Cheer!