为什么 Django 中的 POST 请求有时会起作用，而其他时候则不起作用？ （几乎是随机的）

Question

I have a Django CRUD web app that is basically used to add values to the database, which are visible on the frontend when the page is refreshed and there is a button to edit that entry. It works perfectly fine 90% of the time. But there will be a random instance where someone adds something using the UI and it is added to the database but when refreshed, the entry disappears from the database. It's the most absurd thing I've ever seen. If something was wrong with the code wouldn't it never add it correctly. I'm just confused why it adds values fine 90% of the time but there's that few instances of disappearing entries.

def index(request, user, created_by):
    if request.POST:
        print(request.POST)
        selected_user = request.POST.get('name_user')
        selected_project = request.POST.get('name_project')
        print(selected_user)
        week_starting = request.POST.get('date')
        hours = request.POST.get('hours')
        activity = request.POST.get('activity')
        selected_tag = request.POST.get('tag')
        # check if record already exists for the same user and same week_starting and selected_project
        # if not then insert to DB
        # else don't insert, say record already exists
        if selected_tag == '':
            check_if_exists = TABLENAME.objects.filter(username=selected_user,
                                                                             week_starting=week_starting,
                                                                             project_id=selected_project, tag_id__isnull=True)
        else:
            check_if_exists = TABLENAME.objects.filter(username=selected_user,
                                                                             week_starting=week_starting,
                                                                             project_id=selected_project,
                                                                             tag_id=selected_tag)
        count = check_if_exists.count()
        print("at insert")
        print("how many same records already exist: ", count)
        if count < 1:
            selected_project_id = TABLENAME.objects.only('project_id').get(
                project_id=request.POST.get('project'))
            print(selected_project)
            if selected_tag == '':
                TABLENAME.objects.create(username=selected_user, project_id=selected_project_id,
                                                               week_starting=week_starting, forecast_hours=hours,
                                                               description=activity,
                                                               created_on=timezone.now(), created_by=created_by)
                add_status = "added - no tag"
            else:
                TABLENAME.objects.create(toggl_username=selected_user,
                                                               project_id=selected_project_id,
                                                               week_starting=week_starting, forecast_hours=hours,
                                                               description=activity, tag_id=selected_tag,
                                                               created_on=timezone.now(), created_by=created_by)
                add_status = "added - with tag"
            flash_text = 'Record inserted'
            print(add_status)
            # selected_tag = 0
            return render(request, 'hello_v2.html',
                          {'flash_text': flash_text, 'users': users, 'selected_user': selected_user,
                           'projects': projects, 'date': date, 'tags': tags,
                           'selected_tag': selected_tag, 'selected_project': selected_project})
            # add if tag is not empty then pass tags like here else don't - do the same thing for ID
        else:
            flash_text = 'Record already exists'
            return render(request, 'hello_v2.html',
                          {'flash_text': flash_text, 'users': users, 'selected_user': selected_user,
                           'projects': projects, 'date': date, 'tags': tags, 'selected_tag': selected_tag,
                           'selected_project': selected_project})

    else:
        print("Loading page")
        print(date)
        selected_tag = request.GET.get('tag_id')
        return render(request, 'hello_v2.html', {'users': users, 'date': date, 'projects': projects, 'tags': tags, 'selected_tag': selected_tag})

I'm tracking the POST requests by printing them and in the instances where the entry disappears from the database, I can't see the POST request printed... So I'm really confused I also have an edit method which enables users to edit an entry, sometimes when users edit an entry then it disappears so maybe I have an issue there? But it's only some edits that cause that, not all.

Answer 1

You should check the request like this.

def index(request, user, created_by):
    if request
        print(request.POST)
        selected_user = reques