How to stop duplicate entry into django model - django-forms

Question

I want to stop duplicate entry into form field. If I enter the same data which is already stored into database then it shows an error message or it won't stored. Please Help me guys. I am new in Django.
Form.html File
<form class="well form-horizontal" method="post" action="{% url 'manager_add' %}">
{% csrf_token %}
<fieldset>
<div class="form-group">
<label class="col-md-4 control-label">Manager Name</label>
<div class="col-md-6 inputGroupContainer">
<div class="input-group"><span class="input-group-addon"><i class="glyphicon glyphicon-user"></i></span><input id="fullName" name="mname" placeholder="Full Name" class="form-control" required="true" value="" type="text"></div>
</div>
</div>
<div class="form-group">
<label class="col-md-4 control-label">Select Department</label>
<div class="col-md-6 inputGroupContainer">
<div class="input-group">
<span class="input-group-addon" style="max-width: 100%;"><i class="glyphicon glyphicon-list"></i></span>
<select class="selectpicker form-control" name="dprtmnt">
<option>Department 1</option>
<option>Department 2</option>
<option>Department 3</option>
<option>Department 4</option>
</select>
</div>
</div>
</div>
<div class="form-group">
<label class="col-md-4 control-label">Email</label>
<div class="col-md-6 inputGroupContainer">
<div class="input-group"><span class="input-group-addon"><i class="glyphicon glyphicon-envelope"></i></span><input id="email" name="email" placeholder="Email" class="form-control" required="true" value="" type="text"></div>
</div>
</div>
<div class="form-group">
<label class="col-md-4 control-label">Contact</label>
<div class="col-md-6 inputGroupContainer">
<div class="input-group"><span class="input-group-addon"><i class="glyphicon glyphicon-earphone"></i></span><input id="phoneNumber" name="phone" placeholder="Phone Number" class="form-control" required="true" value="" type="text"></div>
</div>
</div>
<button>Submit</button>
</fieldset>
</form>
Model.py File
class Manager(models.Model):
mname = models.CharField(max_length=20)
dprtmnt = models.CharField(max_length=10)
email = models.CharField(max_length=50)
phone = models.CharField(max_length=20)
def __str__(self):
return self.mname
View.py File
def manager_add(request):
print("Form is submitted successfully!")
mname = request.POST.get("mname", False)
dprtmnt = request.POST.get("dprtmnt", False)
email = request.POST.get("email", False)
phone = request.POST.get("phone", False)
ManagerAdd = Manager(mname = mname, dprtmnt = dprtmnt, email = email, phone = phone, is_active=False)
ManagerAdd.save()
return render(request,'manageradd.html')

Answer 1

You can use Manager.objects.get_or_create(), see this part of the doc.
You can also simple check if an entry already exists in your database:
try:
Manager.objects.get(mname = mname, dprtmnt = dprtmnt, email = email, phone = phone)
# Do things if manager exists
except:
# Create your new manager