How to do data validation from form with data from database?

Question

Django

A small service for tasks is being written.
The page displays all tasks under which forms for entering the correct answer (flag). Tell me how to check the entered data in the form with the desired answer in the database?
views.py

def tasks(request):
    task = Task.objects.all()
    context = {
        'tasks': task,
    }
    if request.method == 'POST':
        form = AnswerForm(request.POST)
        if form.is_valid():
            return HttpResponseRedirect('/result/')
    else:
        form = AnswerForm()
        context = {
            'tasks': task,
            'form': form
        }
    return render(request, 'Socket/task.html', context)

models.py

class Task(models.Model):
    name = models.TextField()
    category = models.TextField()
    right_answer = models.TextField()
    description = models.TextField(blank=True)
    points = models.IntegerField()
    date = models.DateField()
    file = models.FileField(upload_to='/Files/', verbose_name='Файл', blank=True)

template

{% block content %}
{% for task in tasks %}
    <h3>{{ task.name }} - {{ task.points }} очков</h3>
    <h4>Категория - {{ task.category }}</h4>
    <pre>{{ task.description }}</pre>
    <form action="" method="post">
      {% csrf_token %}
       {% bootstrap_form form %}
     {% buttons %}
        <button type="submit" class="btn btn-primary">
            {% bootstrap_icon "ok" %} Ответить
        </button>
    {% endbuttons %}

    </form>
    {% endfor %}
{% endblock %}

The form

class AnswerForm(forms.Form):
    answer = forms.CharField(widget=forms.TextInput, label='Флаг')

Answer 1

It is necessary to override the form.is_valid() method and add a comparison of the entered answer with the true one from the database