Valuerror in admin form - django

Question

Following is my model and form:
models.py
class Employee(models.Model):
id = models.PositiveIntegerField(primary_key=True, verbose_name='Employee Code')
name = models.CharField(max_length=200, verbose_name='Employee Name')
def get_names(self):
return Employee.objects.values_list('name', 'name')
class JobQueue(models.Model):
emp_name = models.ForeignKey(Employee, on_delete=models.CASCADE)
product_code = models.ManyToManyField(Product)
forms.py
class JobQueueForm(forms.ModelForm):
emp = Employee()
prod = Product()
emp_name = forms.ChoiceField(choices = emp.get_names)
product_code = forms.MultipleChoiceField(widget=forms.CheckboxSelectMultiple, choices=prod.get_products)
def save(self, commit=True):
return super(JobQueueForm, self).save(commit = commit)
class Meta:
model = JobQueue
fields = ('emp_name', 'product_code')
When I try to add new employee from JobQueue form, I get the following error:
ValueError at /admin/timesheet/jobqueue/add/
Cannot assign "'some_name'": "JobQueue.emp_name" must be a "Employee" instance.
Any idea what I am doing wrong here?

Answer 1

You have a name clash, basically, which is a red herring for you when debugging this.
You have emp_name in your form which is a ChoiceField (string) but when you save the form to the database the backing model JobQueue is expecting emp_name to be an instance of an employee.
In your case you'd need to override the save method in your form, which you've shown intent on doing already, and fetch the employee there overriding emp_name and saving it.
def save(self, commit=True):
self.emp_name = Employee.objects.get(name=self.cleaned_data['emp_name'])
return super(JobQueueForm, self).save(commit=commit)