python.exe .\manage.py test
Found 7 test(s).
Creating test database for alias 'default'...
System check identified no issues (0 silenced).
E                                                                                                                     
======================================================================                                                
ERROR: setUpClass (crm.test.test_models.TestProjectCode)                                                              
----------------------------------------------------------------------                                                
Traceback (most recent call last):                                                                                    
  File "C:\project\venv\Lib\site-packages\django\db\backends\utils.py", line 89, in _execute
    return self.cursor.execute(sql, params)                                                                           
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\project\venv\Lib\site-packages\django\db\backends\sqlite3\base.py", line 328, in execute
    return super().execute(query, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sqlite3.IntegrityError: UNIQUE constraint failed: crm_project.id

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\project\venv\Lib\site-packages\django\test\testcases.py", line 1466, in setUpClass
    cls.setUpTestData()
  File "C:\project\crm\test\test_models.py", line 12, in setUpTestData
    cls.project = Project.objects.create(name='Test Project', customer=cls.customer)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\project\venv\Lib\site-packages\django\db\models\manager.py", line 87, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\project\venv\Lib\site-packages\django\db\models\query.py", line 658, in create
    obj.save(force_insert=True, using=self.db)
  File "C:\project\crm\models.py", line 242, in save
    return super().save(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\project\venv\Lib\site-packages\django\db\models\base.py", line 814, in save
    self.save_base(
  File "C:\project\venv\Lib\site-packages\django\db\models\base.py", line 877, in save_base
    updated = self._save_table(
              ^^^^^^^^^^^^^^^^^