get_or_create fails when there is a unique field and other values

[kenneth gonsalves <lawgon@…>]

This is for svn head and postgresql backend. Assume a model like this:

class Word(models.Model):
    
    language=models.ForeignKey(Language)
    rootword=models.ForeignKey(Rootword,blank=True,null=True)
    word=models.CharField(_("Word"),maxlength=100,unique=True)
    english=models.CharField(_("English Meaning"),maxlength=500)

I want to dump values from some external source into this table using get_or_create. If the 'word' exists, the no action should be taken, otherwise the row has to be created. If i make my query like this:

a,b = Word.objects.get_or_create(word=wd, language=lng,rootword=rtwd, english=eng)

then unless *all* the fields match in the existing row, django assumes that the row does not exist and attempts to create the row which results in a duplicate key error in postgresql. As a result, the query has to be restricted to 'word' only, to avoid the duplicate key error. If the row containing 'word' is got, then the row has to be updated with the remaining values. If it is created - again it needs to be updated with the remaining values. This could be solved with an update_or_create query?

[Jonathan Buchanan]

Isn't this why the defaults argument exists?

word, created = Word.objects.get_or_create(word=wd, defaults=dict(language=lng, rootword=rtwd, english=eng))

​http://www.djangoproject.com/documentation/db-api/#get-or-create-kwargs

[Nis Jørgensen <nis@…>]

Just for reference, the syntax for using the defaults argument would be

word, created = Word.objects.get_or_create(word=wd, defaults=dict('language':lng, 'rootword': rtwd, 'english':eng))

[James Bennett]

This is pretty much why defaults exists.