django.db.models.fields.related_descriptors.RelatedObjectDoesNotExist通過測試django的形式

Question

我有以下模式：

class Damage(models.Model): 
    kind = models.ForeignKey(Kind, on_delete=models.PROTECT) 
    region = models.ForeignKey(Region, on_delete=models.PROTECT) 

    def clean(self): 
     if self.region not in self.kind.regions.all(): 
      raise ValidationError('not possible') 

和相應的形式：

class DamageForm(forms.ModelForm): 
    class Meta: 
     model = Damage 
     fields = ['kind', 'region'] 

當我運行以下測試，我總是得到django.db.models.fields.related_descriptors.RelatedObjectDoesNotExist: Damage has no region失敗。

def test_empty_input(self): 
    data = { 
     'kind': None, 
     'region': None, 
    } 
    form = DamageForm(data) 
    self.assertFalse(form.is_valid()) 

def test_invalid_input(self): 
    data = { 
     'kind': self.test_kind, 
     'region': self.test_region, 
    } 
    form = DamageForm(data) 
    self.assertFalse(form.is_valid()) 

Answer 1

檢查region_id和self.kind_id不None試圖訪問self.region或self.kind在clean方法之前。

def clean(self): 
    if self.region_id is not None self.kind_id is not None and self.region not in self.kind.regions.all(): 
     raise ValidationError('not possible')