On Thu, Sep 11, 2008 at 8:14 AM, krylatij <[EMAIL PROTECTED]> wrote: > > You can create only one model with empty 'other' field. > If you could create one more, field 'other' will not be unique more. > That's why validation fails. >
This is not generally true at the database level, as Nathaniel showed by the fact that he could indeed create multiple objects with null values, just not via a ModelForm. From the PostgreSQL doc ( http://www.postgresql.org/docs/8.3/interactive/indexes-unique.html): "When an index is declared unique, multiple table rows with equal indexed values will not be allowed. Null values are not considered equal." and MySQL (http://dev.mysql.com/doc/refman/5.0/en/create-index.html): "A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. This constraint does not apply to NULL values except for the BDB storage engine. For other engines, a UNIQUE index allows multiple NULL values for columns that can contain NULL." I don't think the ModelForm validation should prohibit something the databases generally allow. I'd open a ticket (search first though to see if it's already been reported/decided on...I could be missing something). Karen --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
