Why does Model.objects.create() throw a duplicate key value violates unique constraint error?

Question

Django

The error is thrown at the time of saving the object, the problem is that it Model.objects.create()gives the new object the id of an already existing one, checked with a debugger. Why does it do this and how can I make it generate a new one? Until recently, everything was fine and id was generated as it should, but suddenly in one place it stopped working.
Here is the traceback:

Environment:


Request Method: POST
Request URL: http://192.168.10.222:8080/base/add_merop_from_template/1/

Django Version: 2.2
Python Version: 3.8.7
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'debug_toolbar',
 'templatesApp.apps.TemplatesappConfig',
 'changelog.apps.ChangelogConfig',
 'accounts.apps.AccountsConfig',
 'dashboard.apps.DashboardConfig',
 'reference.apps.ReferenceConfig',
 'baseTables.apps.BasetablesConfig',
 'adminTables.apps.AdmintablesConfig',
 'reps.apps.RepsConfig']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'debug_toolbar.middleware.DebugToolbarMiddleware']



Traceback:

File "/usr/local/lib/python3.8/dist-packages/django/db/backends/utils.py" in _execute
  84.                 return self.cursor.execute(sql, params)

The above exception (duplicate key value violates unique constraint "baseTables_merop_pkey"
DETAIL:  Key (id)=(19) already exists.
) was the direct cause of the following exception:

File "/usr/local/lib/python3.8/dist-packages/django/core/handlers/exception.py" in inner
  34.             response = get_response(request)

File "/usr/local/lib/python3.8/dist-packages/django/core/handlers/base.py" in _get_response
  115.                 response = self.process_exception_by_middleware(e, request)

File "/usr/local/lib/python3.8/dist-packages/django/core/handlers/base.py" in _get_response
  113.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/usr/local/lib/python3.8/dist-packages/django/contrib/auth/decorators.py" in _wrapped_view
  21.                 return view_func(request, *args, **kwargs)

File "/usr/local/lib/python3.8/dist-packages/django/contrib/auth/decorators.py" in _wrapped_view
  21.                 return view_func(request, *args, **kwargs)

File "/home/itpw/project/nik/vkmtsup_django/vkmt_sup/baseTables/views.py" in AddMeropFromTemplate
  1748.                 m = Merop.objects.create()

File "/usr/local/lib/python3.8/dist-packages/django/db/models/manager.py" in manager_method
  82.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "/usr/local/lib/python3.8/dist-packages/django/db/models/query.py" in create
  422.         obj.save(force_insert=True, using=self.db)

File "/usr/local/lib/python3.8/dist-packages/django/db/models/base.py" in save
  740.         self.save_base(using=using, force_insert=force_insert,

File "/usr/local/lib/python3.8/dist-packages/django/db/models/base.py" in save_base
  777.             updated = self._save_table(

File "/usr/local/lib/python3.8/dist-packages/django/db/models/base.py" in _save_table
  870.             result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)

File "/usr/local/lib/python3.8/dist-packages/django/db/models/base.py" in _do_insert
  907.         return manager._insert([self], fields=fields, return_id=update_pk,

File "/usr/local/lib/python3.8/dist-packages/django/db/models/manager.py" in manager_method
  82.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "/usr/local/lib/python3.8/dist-packages/django/db/models/query.py" in _insert
  1186.         return query.get_compiler(using=using).execute_sql(return_id)

File "/usr/local/lib/python3.8/dist-packages/django/db/models/sql/compiler.py" in execute_sql
  1332.                 cursor.execute(sql, params)

File "/usr/local/lib/python3.8/dist-packages/django/db/backends/utils.py" in execute
  99.             return super().execute(sql, params)

File "/usr/local/lib/python3.8/dist-packages/django/db/backends/utils.py" in execute
  67.         return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)

File "/usr/local/lib/python3.8/dist-packages/django/db/backends/utils.py" in _execute_with_wrappers
  76.         return executor(sql, params, many, context)

File "/usr/local/lib/python3.8/dist-packages/django/db/backends/utils.py" in _execute
  84.                 return self.cursor.execute(sql, params)

File "/usr/local/lib/python3.8/dist-packages/django/db/utils.py" in __exit__
  89.                 raise dj_exc_value.with_traceback(traceback) from exc_value

File "/usr/local/lib/python3.8/dist-packages/django/db/backends/utils.py" in _execute
  84.                 return self.cursor.execute(sql, params)

Exception Type: IntegrityError at /base/add_merop_from_template/1/
Exception Value: duplicate key value violates unique constraint "baseTables_merop_pkey"
DETAIL:  Key (id)=(19) already exists.

Answer 1

something he picked with his hands in the database, or created manually with the specified id, or touched the counter of the sequence