Django ManyToManyField Validate Unique Set

Question

models.py

class MyProduct(models.Model):
    name = models.CharField()
    codes = models.ManayToManyField(Code)

Hi, I'm trying to validate the ManyToManyField for the unique set. it shoud validate that similar set should not repeat again on another record, In the django docs , it mentioned clearly that ManyToManyField cannot be unique=True or unique_together. So how can I handle this validation, I am not able to find the solution for this. I request please guide me for some suggestion for this, it will be helpfull for me. Thanks in advance.

Answer 1

This is the reference to Array field: https://docs.djangoproject.com/en/3.0/ref/contrib/postgres/fields/

Sample Codes :
Model

class Code(models.Model):
id=models.AutoField(primary_key=True)
codevalue=models.CharField(max_length=50)
def __str__(self):
    return f"{self.codevalue}"
from django.contrib.postgres.fields import ArrayField
class MyProduct(models.Model):
      name = models.CharField(max_length=50)
      codes=models.ManyToManyField(Code)
      codesarray = ArrayField(models.CharField(max_length=50, blank=True, 
      null=True),size=8, blank=True, null=True)

form

class MyProductForm(forms.ModelForm):
    class Meta:
        model=MyProduct
        fields='__all__'

view

from .forms import CodeForm, MyProductForm
from EntityInformation.models import MyProduct
class MyProductView(View):
  template_name = 'EntityInformation/Detail/MyProduct.html'

def get(self, request, name=None):
    myproductform=MyProductForm()
    return render(request, self.template_name, {'form': myproductform})
def post(self,request, name=None):
    myproductform=MyProductForm(request.POST)    
    if myproductform.is_valid():       

        cleaneddata= myproductform.cleaned_data

        arr =[]
        for val in cleaneddata['codes']:
            arr.append(val)        
        try:
            myproductdoc=MyProduct.objects.get(codesarray = arr)
        except:
            myproductdoc=None

        if myproductdoc is None:
            newproductdoc = myproductform.save(commit=False)
            newproductdoc.codesarray=arr
            myproductform.save()
            return render(request, self.template_name, {'form': myproductform})
        else:
            print("Unique validation error")

Above code should help you