This pull request makes a targeted update to how PostgreSQL database
types are specified in the courseware/fields.py file. Specifically,
it changes the type returned for PostgreSQL from BIGSERIAL to BIGINT
in both the db_type and rel_db_type methods. This ensures that
auto-incrementing behavior is not implicitly assumed and aligns with
scenarios where a plain integer type is needed.
This commit introduces several improvements to database migration
scripts to enhance compatibility between MySQL and PostgreSQL, ensure
case-sensitive behavior where needed, and improve migration safety and
correctness. The changes include dynamic SQL generation based on the
database engine, improved transaction handling, and adjustments to
field types and adapters for better cross-database support.
Database compatibility and case sensitivity improvements:
- Migration scripts in split_modulestore_django and learning_sequences
now dynamically generate SQL statements for altering column case
sensitivity and uniqueness based on whether the database is MySQL or
PostgreSQL, ensuring correct behavior across both backends.
- common/djangoapps/split_modulestore_django/migrations/0001_initial.py
- openedx/core/djangoapps/content/learning_sequences/migrations/0001_initial.py
- The courseware.fields module now checks for "postgresql" in the
database engine string instead of a specific backend name, improving
compatibility with different PostgreSQL drivers.
- lms/djangoapps/courseware/fields.py
- The 0011_csm_id_bigint migration in courseware now supports both MySQL
and PostgreSQL for altering column types, with specific SQL for each
backend.
- lms/djangoapps/courseware/migrations/0011_csm_id_bigint.py
- The 0009_readd_facebook_url migration in course_overviews now
introspects the table structure using backend-specific SQL for MySQL
and PostgreSQL, ensuring correct detection of existing fields.
- openedx/core/djangoapps/content/course_overviews/migrations/0009_readd_facebook_url.py
Migration safety and correctness:
- Service user creation and deletion in the commerce app is now wrapped
in atomic transactions to ensure database consistency.
- lms/djangoapps/commerce/migrations/0001_data__add_ecommerce_service_user.py
- The move_overrides_to_edx_when migration in courseware now specifies
a no-op reverse migration, preventing accidental data loss on migration
rollback.
- lms/djangoapps/courseware/migrations/0008_move_idde_to_edx_when.py
Adapter registration and code cleanup:
- The common_initialization app now registers custom adapters for
CourseLocator and related classes in psycopg2 when using PostgreSQL,
ensuring proper serialization of these types.
- openedx/core/djangoapps/common_initialization/apps.py
- Minor code cleanup and formatting improvements in migration files,
including import order and field formatting for readability.
- lms/djangoapps/grades/migrations/0015_historicalpersistentsubsectiongradeoverride.py
