When I am trying to execute django core management code in the function it doesn't work

I need to upload cvs data to database and I wrote the code which did it. but I need to do it triggered: every time user upload file - the python script update the database. In my code: I have call_command('uploadDb') when I place it not in function upload - it works, but when I place it inside the upload function - it didnt What is the problem? Thank you

enter code here
from django.shortcuts import render
import os
from django.core.management import call_command
Create your views here. (file views.py)
from django.http import HttpResponse

def index(request):
return HttpResponse("<h1>Upload the file</h1>")

def home(request):
return render(request, 'index.htm', {'what':'File Upload'})

def upload(request):
if request.method == 'POST':
    handle_uploaded_file(request.FILES['file'], str(request.FILES['file']))
    return HttpResponse("Successful")

  return HttpResponse("Failed")

  def handle_uploaded_file(file, filename):
  if not os.path.exists('upload/'):
    os.mkdir('upload/')

  with open('upload/' + filename, 'wb+') as destination:

    for chunk in file.chunks():
        destination.write(chunk)


 call_command('uploadDb')