Great! this works. Thank you so much Kevin.
2012/3/18 Kevin Wetzels <ke...@roam.be>
>
> On Sunday, March 18, 2012 12:55:31 PM UTC+1, Maarten Japink wrote:
>>
>> I 'm working on a taxonomie.
>> These are my models:
>>
>> class Classificatie(models.Model):
>> name=models.CharField(max_**length=60)
>>
>> def __unicode__(self):
>> return self.name
>>
>> class Taxonomie(models.Model):
>> name=models.CharField(max_**length=60)
>> level=models.ForeignKey(**Classificatie)
>> parent=models.ForeignKey('**self', related_name='parent_id' )
>> synoniem=models.ForeignKey('**self',
>> related_name='synoniem_id' ,blank=True, null=True)
>>
>> I populated the tabels in postgresql
>>
>> When I do:
>> >>>Taxonomie.objects.count()
>> I get the proper number of rows (593)
>>
>> but when i want to read a single object with:
>> >>> t=Taxonomie.objects.get(id=20)
>> Traceback (most recent call last):
>> File "<console>", line 1, in <module>
>> File "C:\Python27\lib\site-**packages\django\db\models\**manager.py",
>> line 132, in
>> get
>> return self.get_query_set().get(***args, **kwargs)
>> File "C:\Python27\lib\site-**packages\django\db\models\**query.py",
>> line
>> 344, in g
>> et
>> num = len(clone)
>> File "C:\Python27\lib\site-**packages\django\db\models\**query.py",
>> line
>> 82, in __
>> len__
>> self._result_cache = list(self.iterator())
>> File "C:\Python27\lib\site-**packages\django\db\models\**query.py",
>> line
>> 286, in i
>> terator
>> obj = model(*row[index_start:**aggregate_start])
>> File "C:\Python27\lib\site-**packages\django\db\models\**base.py",
>> line
>> 297, in __
>> init__
>> setattr(self, field.attname, val)
>> File "C:\Python27\lib\site-**packages\django\db\models\**fields
>> \related.py", line
>> 402, in __set__
>> manager.add(*value)
>> TypeError: add() argument after * must be a sequence, not int
>>
>>
>> I also tried the Taxonomie model with both ' self ' Foreignkey set to
>> blank=True and null=True
>> gives me the same problem. I also can't make new taxonomie objects
>> with django
>>
>>
>> What am I doiing wrong?
>>
>>
> You're using the implicit column_name as the related_name on the
> self-referencing FKs. Django will generate a column name from the name of
> your field, which means parent_id and synoniem_id columns will be used.
> Then you decide to use those as the related_name for the corresponding
> ForeignKey. This won't cause a problem when you perform a count since in
> that case no model instances need to be loaded; it's simply a query that's
> executed.
>
> This works and is more inline with what you should expect of a related
> name:
>
> class Taxonomie(models.Model):
> name=models.CharField(max_length=60)
> level=models.ForeignKey(Classificatie)
> parent=models.ForeignKey('self', related_name='parents' ,blank=True,
> null=True)
> synoniem=models.ForeignKey('self', related_name='synoniemen'
> ,blank=True, null=True)
>
> By the way: if you can, you're better off using English for your code
> rather than Dutch.
>
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