How to add middle IDs in third table with ManyToManyField in Django when using Serialaizer?

Question

I have tables like this:

class Education(models.Model):
    title = models.CharField(default=None, max_length=100)
    content = models.TextField(default=None)
    price = models.ManyToManyField(Price)

class Price(models.Model):
    cost = models.CharField(default=None, max_length=20)

And from client get a request and try to save it in three tables, I have no problem with two tables Education and Price but because I'm using serializer i don't know how to update third table(middle).

def post(self, request):
    cost = request.POST.get('cost')
    price = Price.objects.create(cost=cost)

    education_serializer = EducationSerializer(data=request.data)
    if education_serializer.is_valid():
        education_serializer.save()

Good, here i have updated two tables, In the following i don't know how update third table. If i didn't use serializer i have could write it like this:

education.price.add(price)

Answer 1

The call of education_serializer.save returns an instance of Education, so you can write:

def post(self, request):
    cost = request.POST.get('cost')
    price = Price.objects.create(cost=cost)

    education_serializer = EducationSerializer(data=request.data)
    if education_serializer.is_valid():
        education = education_serializer.save()
        education.price.add(price)