Form Validation passed but Model validation Failed and still the error is showing at form. Can anyon-CodePudding

I have a model Books with one field 'name' and i have set max_length to 10.

class Books(models.Model):
 name = models.CharField(max_length=10)

However, in the modelform BookForm i have defined the max_length to 20.

class BookForm(forms.ModelForm):
 name = forms.CharField(max_length=20)
 class Meta:
    fields = ['name']
    model = Books

Now while submitting the form with more than 10 length it gives me error saying that the field can at most 10 characters.

def book(request):
  if request.method == 'POST':
    fm = BookForm(data=request.POST)
    print(fm.is_valid())
    print(fm)
    if fm.is_valid():
        fm.save()
    return render(request, 'enroll/books.html', {'form':fm})
  fm = BookForm()
  return render(request, 'enroll/books.html', {'form':fm})

enter image description here Can anyone explain why this is happening and any specific article or link where i can read how the model form and models work with each other in terms of validation.

CodePudding user response：

The model form will automatically define the fields based on your Model and its constraints. Since you have defined a name field with max_length validation in Model, you don't require to give it in the form.

class BookForm(forms.ModelForm):
 class Meta:
    fields = ['name']
    model = Books