Данные формы обновляются в базе данных вместо INSERTING

Question

Я хочу сохранить данные формы в базе данных, но когда я нажимаю кнопку отправки, строки в базе данных обновляются, вместо этого INSERTING

с домашней страницы. Я нажимаю на ссылку под названием. fetch_faculty_subject , который будет извлекать некоторые данные из базы данных и отображать вывод в виде выпадающего списка (в HTML).снова из form Я добавляю некоторые данные в форму и сохраняю в таблицу с именем Mapped_faculty_n_subjects

это мои views.py

def fetch_faculty_subject(request):
    faculties= facultyhours.objects.filter(user_id = request.user.id)
    subjects= subject_code.objects.filter(user_id = request.user.id)
    classname= class_number.objects.filter(user_id = request.user.id)
    context1 = {
         'faculties': faculties,
         'subjects': subjects,
         'classes': classname
     }
    return render(request, 'createtimetable_for_class/selecting_subjects_n_teachers.html', context1)


def store_the_faculty_subject(request):
    userr = request.user.id
    selected_class_name=request.POST["classname"]
    selected_faculty_name=request.POST["facultyname"]
    selected_subject_name=request.POST["subjectname"]
    selected_total_hours_per_week=request.POST["totalhours"]
    faculty_n_subject_db=Mapped_faculty_n_subjects(selected_class_name=selected_class_name,selected_faculty_name=selected_faculty_name,selected_subject_name=selected_subject_name,selected_total_hours_per_week=selected_total_hours_per_week,user_id=userr)
    faculty_n_subject_db.save()
    # return redirect('/fetch_faculty_subject/')

    faculties= facultyhours.objects.filter(user_id = request.user.id)
    subjects= subject_code.objects.filter(user_id = request.user.id)
    classname= class_number.objects.filter(user_id = request.user.id)
    context1 = {
         'faculties': faculties,
         'subjects': subjects,
         'classes': classname
     }
    # return redirect(request,'createtimetable_for_class/selecting_subjects_n_teachers.html',context1)
    return render(request, 'createtimetable_for_class/selecting_subjects_n_teachers.html',context1)

это моя models.py

class Mapped_faculty_n_subjects(models.Model):
    selected_class_name=models.CharField(max_length=250,primary_key=True)
    selected_faculty_name=models.CharField(max_length=250)
    selected_subject_name=models.CharField(max_length=250)
    selected_total_hours_per_week=models.CharField(max_length=250)
    user = models.ForeignKey(User, on_delete=models.CASCADE, blank=True)

это моя HTML-форма

{% extends 'base.html' %}
{% load crispy_forms_tags %}
{% block content %}
<div class="row justify-content-center">
    <div class="col-6">
        <div class="card">
            <div class="card-body">
                <h2>Select Faculty and Subject</h2>
                    <form method="post" action="/store_the_faculty_subject/">
                        {% csrf_token %}
                        {{ form|crispy }}
                            <label>Select The Class</label><br>
                            <select name="classname">
                                 {% for classes in classes %}
                                <option>{{ classes.class_name }}</option>
                                {% endfor %}
                            </select><br><br>
                            <label>Select The Faculty</label><br>
                            <select name="facultyname">
                                 {% for faculty in faculties %}
                                <option>{{ faculty.faculty_name }}</option>
                                {% endfor %}
                            </select><br><br>
                            <label>Select The Subject</label><br>
                            <select name="subjectname">
                                {% for subjects in subjects %}
                                <option>{{ subjects.subject_name }}</option>
                                {% endfor %}

                            </select><br><br>
                            <label>Total hours per week</label><br>
                            <input type="number" max="34" name="totalhours" required class="textinput textInput form-control"><br>
                            <button type="submit" class="btn btn-primary">SUBMIT</button>
                        <a class="btn btn-secondary" href="#">NEXT</a>

                    </form>
            </div>
        </div>
    </div>

</div>
{% endblock %}