Oh I agree they are both very bad. Putting NULL in a non-NULL field is totally wrong.
However I really do think that inserting an unexpected default value is worse than inserting NULL into a NON-NULL field. The NULLs will cause problems, but they are problems you can see and resolve.
The default values are silent errors that will corrupt your data and be very difficult to recover from in the future. You can only guess which data was wrongly inserted.
However I really do think that inserting an unexpected default value is worse than inserting NULL into a NON-NULL field. The NULLs will cause problems, but they are problems you can see and resolve.
The default values are silent errors that will corrupt your data and be very difficult to recover from in the future. You can only guess which data was wrongly inserted.