Помогите Cannot INSERT into generated column. Как исправить?

from django.forms.widgets import TextInput
from .models import PriceTable
from django.forms import ModelForm


class PriceTableForm(ModelForm):
    class Meta:
        model = PriceTable
        fields = [
                    'сipher',
                    'transparency',
                    'color',
                    'pis',
                    'purity',
                    'intensity',
                    'typicality',
                    'purity2',
                    'intensity2',
                    'persistence',
                    'typicality2',
                    'harmony',
                    'outcome',
                    'description',
                    'taster',
                    'date',
                 ]

from django.db import models
from django.db.models.base import Model


# Create your models here.


class PriceTable(models.Model):
    сipher = models.CharField(max_length=6, default='*', verbose_name='Шифр')
    transparency = models.DecimalField(max_digits=3, decimal_places=1, default=0.5, verbose_name='Прозрачность')
    color = models.DecimalField(max_digits=3, decimal_places=1, default=0.5, verbose_name='Цвет')
    pis = models.DecimalField(max_digits=3, decimal_places=1, default=0, verbose_name='Пенистые и игристые свойства')
    purity = models.DecimalField(max_digits=3, decimal_places=1, default=0.8, verbose_name='Чистота')
    intensity = models.DecimalField(max_digits=3, decimal_places=1, default=0.9, verbose_name='Интенсивность')
    typicality = models.DecimalField(max_digits=3, decimal_places=1, default=0.8, verbose_name='Типичность')
    purity2 = models.DecimalField(max_digits=3, decimal_places=1, default=1.4, verbose_name='Чистота')
    intensity2 = models.DecimalField(max_digits=3, decimal_places=1, default=1.4, verbose_name='Интенсивность')
    persistence = models.DecimalField(max_digits=3, decimal_places=1, default=1.4, verbose_name='Интенсивность')
    typicality2 = models.DecimalField(max_digits=3, decimal_places=1, default=1.4, verbose_name='Типичность')
    harmony = models.DecimalField(max_digits=3, decimal_places=1, default=0.8, verbose_name='Гармония и общее впечатление')
    outcome = models.CharField(max_length=20,blank=True, null=True, verbose_name='Итого')
    description = models.CharField(max_length=200, default='Органолептические показатели: Прозрачное, без осадка и посторонних включений.', verbose_name='Описание')
    taster = models.CharField(max_length=20, default='Дегустатор', verbose_name='Дегустатор')
    date = models.CharField(max_length=10,default= '10.12.2021', verbose_name='Дата')
     

    def __str__(self):
        return self.сipher

    class Meta:
        ordering = ['-id',]
        verbose_name = 'Образец'
        verbose_name_plural = 'Образцы'

from django import forms
from django.db import models
from django.http.request import HttpRequest
from django.shortcuts import render, redirect
from maintable.models import PriceTable
from maintable.forms import PriceTableForm
from django.contrib import messages
from django.http import HttpResponseRedirect
from django.views.generic.edit import CreateView
from django.db.models import Sum




# Create your views here.
def login(request):
    return render(request, './login.html')

def first_page(request):
    error = ''
    if request.method == 'POST':
        form = PriceTableForm(request.POST)
        if form.is_valid():
            form.save(); 
            messages.success(request, 'Форма отправлена')
            return HttpResponseRedirect('/home')
        else:
            error = 'Обнаружены ошибки, заполни снова!'
  

    form = PriceTableForm
    price_table = PriceTable.objects.all()
    dict_obj = { 
                'price_table': price_table,
                'form': form,
                'error': error
                }
    return render(request, './base.html', dict_obj)