Fix data migration erroring if a record exists

[rhysyngsun]

What are the relevant tickets?

N/A

Description (What does it do?)

Fixes an insert error if you already have a record that exists that this migration is trying to add.

How can this be tested?

I'm not quite sure how I got in this state, but the migration was conflicting trying to insert this record:

  Apply all migrations: admin, articles, auth, authentication, channels, contenttypes, data_fixtures, guardian, learning_resources, learning_resources_search, news_events, oauth2_provider, profiles, sessions, sites, social_django, testimonials, widgets
Running migrations:
  Applying data_fixtures.0001_add_testimonial_data... OK
  Applying data_fixtures.0002_unit_page_copy_updates... OK
  Applying data_fixtures.0003_unit_page_copy_updates... OK
  Applying data_fixtures.0004_upsert_initial_topic_data... OK
  Applying data_fixtures.0005_unit_page_copy_updates... OK
  Applying data_fixtures.0006_update_parent_topic_channel_descriptions... OK
  Applying data_fixtures.0007_topic_mappings_edx_add_programming_coding_to_computer_science... OK
  Applying data_fixtures.0008_unpublish_empty_topic_channels... OK
  Applying data_fixtures.0009_topics_update_engineering_add_manufacturing... OK
  Applying data_fixtures.0010_topics_update_icons_for_innovation_data_science... OK
  Applying data_fixtures.0011_unit_page_copy_updates... OK
  Applying data_fixtures.0012_topic_mappings_adjust_sustainable_business_finance_accounting... OK
  Applying data_fixtures.0013_remove_department_RES... OK
  Applying data_fixtures.0014_add_department_SP...Traceback (most recent call last):
  File "/opt/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 89, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
psycopg2.errors.UniqueViolation: duplicate key value violates unique constraint "learning_resources_learningresourcedepartmentnew_pkey"
DETAIL:  Key (department_id)=(SP) already exists.


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

Traceback (most recent call last):
  File "/src/./manage.py", line 29, in <module>
    execute_from_command_line(sys.argv)
  File "/opt/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
    utility.execute()
  File "/opt/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 436, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/opt/venv/lib/python3.12/site-packages/django/core/management/base.py", line 412, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/opt/venv/lib/python3.12/site-packages/django/core/management/base.py", line 458, in execute
    output = self.handle(*args, **options)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/core/management/base.py", line 106, in wrapper
    res = handle_func(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/core/management/commands/migrate.py", line 356, in handle
    post_migrate_state = executor.migrate(
                         ^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/migrations/executor.py", line 135, in migrate
    state = self._migrate_all_forwards(
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/migrations/executor.py", line 167, in _migrate_all_forwards
    state = self.apply_migration(
            ^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/migrations/executor.py", line 252, in apply_migration
    state = migration.apply(state, schema_editor)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/migrations/migration.py", line 132, in apply
    operation.database_forwards(
  File "/opt/venv/lib/python3.12/site-packages/django/db/migrations/operations/special.py", line 193, in database_forwards
    self.code(from_state.apps, schema_editor)
  File "/src/data_fixtures/migrations/0014_add_department_SP.py", line 33, in add_sp
    department = LearningResourceDepartment.objects.create(
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/manager.py", line 87, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/query.py", line 658, in create
    obj.save(force_insert=True, using=self.db)
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/base.py", line 814, in save
    self.save_base(
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/base.py", line 877, in save_base
    updated = self._save_table(
              ^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/base.py", line 1020, in _save_table
    results = self._do_insert(
              ^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/base.py", line 1061, in _do_insert
    return manager._insert(
           ^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/manager.py", line 87, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/query.py", line 1805, in _insert
    return query.get_compiler(using=using).execute_sql(returning_fields)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/models/sql/compiler.py", line 1822, in execute_sql
    cursor.execute(sql, params)
  File "/opt/venv/lib/python3.12/site-packages/sentry_sdk/utils.py", line 1730, in runner
    return sentry_patched_function(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/sentry_sdk/integrations/django/__init__.py", line 651, in execute
    result = real_execute(self, sql, params)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 67, in execute
    return self._execute_with_wrappers(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 80, in _execute_with_wrappers
    return executor(sql, params, many, context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 84, in _execute
    with self.db.wrap_database_errors:
  File "/opt/venv/lib/python3.12/site-packages/django/db/utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/opt/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 89, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
django.db.utils.IntegrityError: duplicate key value violates unique constraint "learning_resources_learningresourcedepartmentnew_pkey"
DETAIL:  Key (department_id)=(SP) already exists.

Additional Context

[jonkafton]

Looks good!

Tested on a fresh local db:

docker compose down db
docker volume rm <project_name>_pgdata

The migrations are applied successfully with:

docker compose run web python manage.py migrate