"DatabaseError: duplicate column name" - bug with custom model's abstract class in django test

Question

I am new in django testing. When I try python manage.py test, it generates error below:

    output = self.handle(*args, **options)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/core/management/commands/test.py", line 90, in handle
    failures = test_runner.run_tests(test_labels)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/test/runner.py", line 210, in run_tests
    old_config = self.setup_databases()
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/test/runner.py", line 166, in setup_databases
    **kwargs
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/test/runner.py", line 370, in setup_databases
    serialize=connection.settings_dict.get("TEST", {}).get("SERIALIZE", True),
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/backends/base/creation.py", line 368, in create_test_db
    test_flush=not keepdb,
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 120, in call_command
    return command.execute(*args, **defaults)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/core/management/base.py", line 441, in execute
    output = self.handle(*args, **options)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 221, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/migrations/executor.py", line 110, in migrate
    self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/migrations/executor.py", line 147, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/migrations/migration.py", line 115, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/migrations/operations/fields.py", line 62, in database_forwards
    field,
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/backends/mysql/schema.py", line 43, in add_field
    super(DatabaseSchemaEditor, self).add_field(model, field)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/backends/base/schema.py", line 398, in add_field
    self.execute(sql, params)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/backends/base/schema.py", line 111, in execute
    cursor.execute(sql, params)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/utils.py", line 97, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/django/db/backends/mysql/base.py", line 124, in execute
    return self.cursor.execute(query, args)
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/MySQL_python-1.2.5-py2.7-linux-x86_64.egg/MySQLdb/cursors.py", line 205, in execute
  File "/home/gaurav/PyProjects/myenv/local/lib/python2.7/site-packages/MySQL_python-1.2.5-py2.7-linux-x86_64.egg/MySQLdb/connections.py", line 36, in defaulterrorhandler
django.db.utils.OperationalError: (1060, "Duplicate column name 'created_at'")

What I tried so far:

For a single app;

1. python manage.py test equity_funds_investor_app --settings=mysettings

For Complete project;

2. python manage.py test --settings=equity_funds.settings

Still getting the same error :(.

Answer 1

As error msg suggest >> "Duplicate column name 'created_at'" migration try to
recreate the existing column "created_at".

For development environment simple solution is to
Drop migrations folder and Create migrations again.