title: Django Migration not starting on ubuntu
body: <p>i have uploaded my Django project to an ubuntu server. and deleted all migration files on project folder. I was using mysql on my localhost, but installed Postgresql on Ubuntu. When i try to migrate database django raises errors like  below.</p>
  
  <p>python manage.py migrate results in</p>
  
  <pre><code> F File "manage.py", line 15, in &lt;module&gt;
      execute_from_command_line(sys.argv)
    File "/root/Virtual/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
      utility.execute()
    File "/root/Virtual/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
      self.fetch_command(subcommand).run_from_argv(self.argv)
    File "/root/Virtual/lib/python3.7/site-packages/django/core/management/base.py", line 323, in run_from_argv
      self.execute(*args, **cmd_options)
    File "/root/Virtual/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 60, in execute
      super().execute(*args, **options)
    File "/root/Virtual/lib/python3.7/site-packages/django/core/management/base.py", line 364, in execute
      output = self.handle(*args, **options)
    File "/root/Virtual/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 95, in handle
      self.run(**options)
    File "/root/Virtual/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 102, in run
      autoreload.run_with_reloader(self.inner_run, **options)
    File "/root/Virtual/lib/python3.7/site-packages/django/utils/autoreload.py", line 579, in run_with_reloader
      start_django(reloader, main_func, *args, **kwargs)
    File "/root/Virtual/lib/python3.7/site-packages/django/utils/autoreload.py", line 564, in start_django
      reloader.run(django_main_thread)
    File "/root/Virtual/lib/python3.7/site-packages/django/utils/autoreload.py", line 272, in run
      get_resolver().urlconf_module
    File "/root/Virtual/lib/python3.7/site-packages/django/utils/functional.py", line 80, in __get__
      res = instance.__dict__[self.name] = self.func(instance)
    File "/root/Virtual/lib/python3.7/site-packages/django/urls/resolvers.py", line 564, in urlconf_module
      return import_module(self.urlconf_name)
    File "/root/Virtual/lib/python3.7/importlib/__init__.py", line 127, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File "&lt;frozen importlib._bootstrap&gt;", line 1006, in _gcd_import
    File "&lt;frozen importlib._bootstrap&gt;", line 983, in _find_and_load
    File "&lt;frozen importlib._bootstrap&gt;", line 967, in _find_and_load_unlocked
    File "&lt;frozen importlib._bootstrap&gt;", line 677, in _load_unlocked
    File "&lt;frozen importlib._bootstrap_external&gt;", line 728, in exec_module
    File "&lt;frozen importlib._bootstrap&gt;", line 219, in _call_with_frames_removed
    File "/root/Virtual/AdenOnline/AdenOnline/urls.py", line 13, in &lt;module&gt;
      path('taskmanager/',include('taskmanager.urls') ),
    File "/root/Virtual/lib/python3.7/site-packages/django/urls/conf.py", line 34, in include
      urlconf_module = import_module(urlconf_module)
    File "/root/Virtual/lib/python3.7/importlib/__init__.py", line 127, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File "&lt;frozen importlib._bootstrap&gt;", line 1006, in _gcd_import
    File "&lt;frozen importlib._bootstrap&gt;", line 983, in _find_and_load
    File "&lt;frozen importlib._bootstrap&gt;", line 967, in _find_and_load_unlocked
    File "&lt;frozen importlib._bootstrap&gt;", line 677, in _load_unlocked
    File "&lt;frozen importlib._bootstrap_external&gt;", line 728, in exec_module
    File "&lt;frozen importlib._bootstrap&gt;", line 219, in _call_with_frames_removed
    File "/root/Virtual/AdenOnline/taskmanager/urls.py", line 6, in &lt;module&gt;
      from .views import MainView,TaskDetailView,TaskListView
    File "/root/Virtual/AdenOnline/taskmanager/views.py", line 107, in &lt;module&gt;
      class TaskListView(ListView):
    File "/root/Virtual/AdenOnline/taskmanager/views.py", line 110, in TaskListView
      queryset = list(Task.objects.all().values('id','task_project','task_title','task_employee','task_employer','task_start_date','task_end_date','task_status','task_priorty'))
    File "/root/Virtual/lib/python3.7/site-packages/django/db/models/query.py", line 274, in __iter__
      self._fetch_all()
    File "/root/Virtual/lib/python3.7/site-packages/django/db/models/query.py", line 1242, in _fetch_all
      self._result_cache = list(self._iterable_class(self))
    File "/root/Virtual/lib/python3.7/site-packages/django/db/models/query.py", line 113, in __iter__
      for row in compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size):
    File "/root/Virtual/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 1049, in results_iter
      results = self.execute_sql(MULTI, chunked_fetch=chunked_fetch, chunk_size=chunk_size)
    File "/root/Virtual/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 1097, in execute_sql
      cursor.execute(sql, params)
    File "/root/Virtual/lib/python3.7/site-packages/django/db/backends/utils.py", line 99, in execute
      return super().execute(sql, params)
    File "/root/Virtual/lib/python3.7/site-packages/django/db/backends/utils.py", line 67, in execute
      return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
    File "/root/Virtual/lib/python3.7/site-packages/django/db/backends/utils.py", line 76, in _execute_with_wrappers
      return executor(sql, params, many, context)
    File "/root/Virtual/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
      return self.cursor.execute(sql, params)
    File "/root/Virtual/lib/python3.7/site-packages/django/db/utils.py", line 89, in __exit__
      raise dj_exc_value.with_traceback(traceback) from exc_value
    File "/root/Virtual/lib/python3.7/site-packages/django/db/backends/utils.py", line 84, in _execute
      return self.cursor.execute(sql, params)
  django.db.utils.ProgrammingError: relation "taskmanager_task" does not exist
  LINE 1: ...k_status", "taskmanager_task"."task_priorty" FROM "taskmanag...
  </code></pre>
  
  <p>Does this because of i switched PostgreSQL on server or Django ? Any ideas  and suggestions will be appreciated. Thank a lot.</p>