Django: Check if updated field is already present in database - django

Question

I am trying to update a django ModelForm with email as a field. In the create form, I am checking if the field is already present in database, if so raise validation error. That part is working as expected.
however, if I use the same check in update form, it throws validation error as the existing record has the given email. Is there a direct method to ensure this validation?
forms.py
class MyObjCreateForm(forms.ModelForm):
first_name = forms.CharField(max_length=50, label='First name')
last_name = forms.CharField(max_length=50, label='Last name')
email = forms.EmailField(label='Email')
location = forms.ChoiceField(choices=TP_TM_Location, label='Location')
designation = forms.ChoiceField(choices=TP_TM_Designation, label='Designation')
date_of_joining = forms.DateField(label='Date of joining',
widget=forms.TextInput(attrs={'type': 'date'}),
initial=date.today())
username = forms.CharField(label='Login username')
password = forms.CharField(widget=forms.PasswordInput(), label='Login password')
current_status = forms.ChoiceField(choices=TP_Status, label='Current status')
def clean_email(self):
email = self.cleaned_data.get('email')
try:
match = MyObj.objects.get(email=email)
raise forms.ValidationError("email already exists in system. Please check the existing list.")
except MyObj.DoesNotExist:
return email
class MyObjUpdateForm(forms.ModelForm):
first_name = forms.CharField(max_length=50, label='First name')
last_name = forms.CharField(max_length=50, label='Last name')
email = forms.EmailField(label='Email')
location = forms.ChoiceField(choices=TP_TM_Location, label='Location')
designation = forms.ChoiceField(choices=TP_TM_Designation, label='Designation')
date_of_joining = forms.DateField(label='Date of joining',
widget=forms.TextInput(attrs={'type': 'date'}),
initial=date.today())
current_status = forms.ChoiceField(choices=TP_Status, label='Current status')
username = forms.CharField(label='Login username')
def clean_email(self):
email = self.cleaned_data.get('email')
try:
match = MyObj.objects.get(email=email)
raise forms.ValidationError("email already exists in system. Please check the existing list.")
except MyObj.DoesNotExist:
return email
Thanks,

Answer 1

For this you need to exclude the current user from the queryset like this .
def clean_email(self):
email = self.cleaned_data.get('email')
email_match = MyObj.objects.filter(email=email).exclude(pk=self.instance.pk)
if self.instance and self.instance.pk and not email_match:
return email
else:
raise forms.ValidationError("email already exists in system. Please check the existing list.")

Answer 2

You need to remove the validation in update class. You can simply return the email without validation.
def clean_email(self):
return self.cleaned_data.get('email')
However, if you want to check if the user already has the new email,then you can use following validation method:
def clean_email(self):
email = self.cleaned_data.get('email')
if self.instance.email == email:
raise forms.ValidationError("Email already present.")
return email