On Sun, Apr 13, 2008 at 9:48 PM, steve skelton <[EMAIL PROTECTED]> wrote:
> > thanks - I've tried it both ways and with __str__ get the error > > __str__ returned non-string (type NoneType). > That's odd... > the top-level error dump is > > Request Method: GET > Request URL: http://localhost:8000/admin/papers_admin/paper/35/ > Exception Type: TypeError > Exception Value: __str__ returned non-string (type NoneType) > Exception Location: C:\Python25\lib\site-packages\django\db\models > \fields\__init__.py in get_choices, line 302 > > all the models where I apply > > __str__ are of the form > > class LuPaperContentRegion(models.Model): > paper_content_region = models.CharField(maxlength=150) > > def __str__(self): > return self.paper_content_region > > class Meta: > db_table='lu_paper_content_region' Are you building these models from scratch with a new database or working with a pre-existing database? The fact you are specifying db_table in Meta makes me think maybe you are trying to map models over an already-existing table? Which can be done, but if the Django model definition isn't correctly mapping the real table it might lead to problems. Right now as that model is defined to Django, the Django admin would not allow paper_content_region to be set to null, which is the only way I can think of that your __str__() would return None. So I'm confused how you are getting this error. list to the FK model as > > Country = models.ForeignKey(LuCountry) > > since this would be a link to the LuCountry table by the ID and my > expectation is this might display the ID in the linked table, not a > string so perhaps this may be the source of the problem -- but that is > just a guess. > Now, the target for the ForeignKey here is LuCountry, which we haven't seen before. Is this the one having a problem or is it the one with LuPaperContentRegion? If its LuCountry that's having the problem that's the model we need to see. To back up to a conceptual level, what the admin is trying to do is build a list of all possible targets for this foreign key, in human-readable form, for the select drop-down box. Under the covers it will know the primary key ID of each of the elements in the list, and that is what will be stored in the table when you select one, but to make it easier to select the right one it is going to present the user a friendly list. So it's essentially going to select all the elements in the target table and call your __str__ function for each one. (There is an option to turn this off and force the user to enter raw IDs for cases where your tables are too large for this approach to work well, but you're not using that here.) So, if you are working with a pre-existing table, any null values in fields you are returning with __str__ could be causing this problem. And that's about the only wild guess I have right now to explain what you are seeing. Karen > Thanks for your response - hopefully there is a simple thing I am not > getting. > > On Apr 13, 8:35 pm, Michael <[EMAIL PROTECTED]> wrote: > > Try changing __unicode__ to __str__. The unicode merge was after .96 and > > therefore it isn't looking for __unicode__ to define the name of the > field. > > > > Hope that helps, > > > > Michael > > > > On Sun, Apr 13, 2008 at 9:28 PM, steve skelton < > [EMAIL PROTECTED]> > > wrote: > > > > > > > > > sorry I forgot to specify - am using 0.96.1 (django) and MySQL 5.0.51a > > > (server) and 5.1.11 (client) and my local install is on Vista laptop > > > with Apache and PHP also installed. > > > > > On Apr 13, 8:24 pm, steve skelton <[EMAIL PROTECTED]> wrote: > > > > Trying to get admin on my system to load values based on related > > > > tables on db. I have set the FK on the papers table to tie with the > > > > PK of each look-up table and set models like so: > > > > > > class LuPaperContentEra(models.Model): > > > > paper_content_era = models.CharField(blank=True, maxlength=150) > > > > > > def __unicode__(self): > > > > return self.paper_content_era > > > > > > class Meta: > > > > db_table='lu_paper_content_era' > > > > > > The main table, which should contain drop-downs for things like the > > > > model/table above, has things like: > > > > > > class Paper(models.Model): > > > > ... many fields defined > > > > PaperContent_Era = models.ForeignKey(LuPaperContentEra) > > > > ... more fields defined > > > > > > class Meta: > > > > db_table='papers_admin' > > > > > > class Admin: > > > > list_display=('id','FirstName','LastName','Institution') > > > > search_fields=['LastName'] > > > > > > However, Admin displays the drop-down as > > > > > > LuPaperContactEra object, NOT the actual human-readable value list. > > > > > > I feel I am probably close to getting this to work but can't seem to > > > > find the right direction in which to be "nudged". > > > > > > Thanks! > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. 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