Fields with default values shouldn't need to be nullable
Closed this issue · 7 comments
class BaseModel(TypedModel):
some_fields = ...
class MyModel(BaseModel):
field = models.BooleanField(default=False)
result
SystemCheckError: System check identified some issues:
ERRORS:
app.BaseModel.field: (fields.E110) BooleanFields do not accept null values.
HINT: Use a NullBooleanField instead.
Interesting.
typedmodels forces all fields defined on subclasses to null=True, since they're not defined for all possible types.
(aside: I wasn't aware that django had a NullBooleanField, I wonder why that's there? I'd guess something to do with HTML widgets - you need a dropdown for a three-state thing instead of a checkbox.)
I don't think there's a reasonable thing that typedmodels can do here. If it magically changed your field into a NullBooleanField it'd break things that you might not expect to break, like form field types etc.
So probably the only thing we can do to improve this is add it to the docs?
or just skip processing boolean fields
Can't just skip it - the field has to be nullable, or you wouldn't be able to insert into the table from another BaseModel subclass. So I think there'd be two possible solutions:
- force the caller to decide how it behaves. You can either add it to
BaseModeland set a true/false default value, or change it toNullBooleanField - typedmodels could do some nasty magic, like forcing the db column to nullable even though the field isn't nullable. This would require messing with migrations in a way I'm not even sure is possible.
I'm definitely -1 on the latter. The right solution is to doc the limitation and make the user make the call.
my field has default, it doesn have to be nullable
good point.