Add support for table comment evolutions in Django 4.2+.

Review Request #13344 — Created Oct. 14, 2023 and submitted

Information

Django Evolution
release-2.x

Reviewers

Django 4.2 introduced table comments. These are comments that are part
of the table schema, describing a table, and are supported in MySQL 8+
and Postgres 12+ (the minimum versions that Django 4.2 supports), but
not SQLite.

This supports signature storage of table comments and evolutions via
ChangeMeta.

This functionality is required for Django 4.2 support, as this is
introspected on our mock models, and we don't want to risk storing empty
values or misleading the backend. Fortunately, as we can piggy-back on
SchemaEditor, support is easy to add and maintain going forward.

Ran unit tests for SQLite, Postgres, and MySQL on a range of database
versions on Python 3.11 and 3.12, Django 3.2-4.2, which should provide
sufficient coverage for this feature.

Summary ID
Add support for table comment evolutions in Django 4.2+.
Django 4.2 introduced table comments. These are comments that are part of the table schema, describing a table, and are supported in MySQL 8+ and Postgres 12+ (the minimum versions that Django 4.2 supports), but not SQLite. This supports signature storage of table comments and evolutions via `ChangeMeta`. This functionality is required for Django 4.2 support, as this is introspected on our mock models, and we don't want to risk storing empty values or misleading the backend. Fortunately, as we can piggy-back on `SchemaEditor`, support is easy to add and maintain going forward.
7cc43485b6cc9772eb4417959bb8b6c84ec45d56
david
  1. Ship It!
  2. 
      
chipx86
Review request changed
Status:
Completed
Change Summary:
Pushed to release-2.x (744905f)