django模型验证不起作用

from django.core.exceptions import ValidationError
from django.db import models

def validate_even(value):
    if value % 2 != 0:
        raise ValidationError('%s is not an even number' % value)

class MyModel(models.Model):
    even_number = models.IntegerField(validators=[validate_even])

from django.http import JsonResponse
from django.views import View
from .models import MyModel

class MyView(View):
    def post(self, request):
        data = request.POST
        my_model = MyModel(even_number=data['even_number'])
        try:
            my_model.full_clean()
        except ValidationError as e:
            return JsonResponse({'error': str(e)})
        my_model.save()
        return JsonResponse({'success': True})

from django import forms
from django.core.exceptions import ValidationError
from django.db import models

class MyModel(models.Model):
    even_number = models.IntegerField()

class MyModelForm(forms.ModelForm):
    class Meta:
        model = MyModel
        fields = ['even_number']

    def clean_even_number(self):
        data = self.cleaned_data['even_number']
        if data % 2 != 0:
            raise ValidationError('%s is not an even number' % data)
        return data