when i update/edit data is duplicated instead of being updated in django - python-3.x

Question

data is duplicated instead of being updated in django, please help me to overcome this i also tried update method but issues i have faced is image not displayed, therefore i is used save method which will save and make copy of anthor object which i dont want. it should update the same object.
views.py
def EuAdmin(request, pk):
pi = EmailDb.objects.get(id=pk)
if request.method == 'POST':
institution = request.POST.get('institution', '')
fullname = request.POST.get('fullname', '')
email = request.POST.get('email', '')
contact = request.POST.get('contact', '')
position = request.POST.get('position', '')
uploadd = request.FILES.get('upload', '')
sdata = EmailDb(institution=institution, fullname=fullname, contact=contact, email=email, position=position, uploaddata=uploadd)
sdata.save()
return HttpResponseRedirect("/eadmin")
return render(request, 'NEC/eupdate.html', {'pi': pi})
models.py
class EmailDb(models.Model):
institution = models.CharField(max_length=300, blank=True, null=True)
fullname = models.CharField(max_length=50, blank=True, null=True)
contact = models.IntegerField()
email = models.CharField(max_length=300, blank=True, null=True)
position = models.CharField(max_length=100, blank=True, null=True)
uploaddata = models.FileField(upload_to='appointment_letter')
def __str__(self):
return self.fullname

Answer 1

That's because you create a new EmailDb object. You can edit the one with:
from django.shortcuts import get_object_or_404
def EuAdmin(request, pk):
pi = get_object_or_404(EmailDb, pk=pk)
if request.method == 'POST':
institution = request.POST.get('institution', '')
fullname = request.POST.get('fullname', '')
email = request.POST.get('email', '')
contact = request.POST.get('contact', '')
position = request.POST.get('position', '')
uploaded = request.FILES.get('upload', '')
pi.institution = institution
pi.fullname = fullname
pi.contact = contact
pi.email = email
pi.position = position
pi.uploaddata = uploaded
pi.save()
return HttpResponseRedirect('/eadmin')
return render(request, 'NEC/eupdate.html', {'pi': pi})
Note: It is better to use a Form [Django-doc]
than to perform manual validation and cleaning of the data. A Form will not
only simplify rendering a form in HTML, but it also makes it more convenient
to validate the input, and clean the data to a more convenient type.
Note: Models normally have no Db suffix. A model is not a table, it is stored in a relational database as a table, but even then it has extra logic like validators, managers, etc.
Note: Please use an EmailField [Django-doc] instead of a CharField [Django-doc] to store an email address, this can do validation to check if the entered data is indeed an email address.
Note: It is often better to use get_object_or_404(…) [Django-doc],
then to use .get(…) [Django-doc] directly. In case the object does not exists,
for example because the user altered the URL themselves, the get_object_or_404(…) will result in returning a HTTP 404 Not Found response, whereas using
.get(…) will result in a HTTP 500 Server Error.

Answer 2

sdata = EmailDb(institution=institution, fullname=fullname, contact=contact, email=email, position=position, uploaddata=uploadd)
sdata.save()
This performs an INSERT SQL statement.
Since you already have object just set the value and call save() as
def EuAdmin(request, pk):
pi = EmailDb.objects.get(id=pk)
if request.method == 'POST':
institution = request.POST.get('institution', '')
fullname = request.POST.get('fullname', '')
email = request.POST.get('email', '')
contact = request.POST.get('contact', '')
position = request.POST.get('position', '')
uploaded = request.FILES.get('upload', '')
pi.institution = institution
pi.fullname = fullname
pi.contact = contact
pi.email = email
pi.position = position
pi.uploaddata = uploaded
pi.save()
return HttpResponseRedirect("/eadmin")
return render(request, 'NEC/eupdate.html', {'pi': pi})