GeezerVison

suggestion (code_clarification): Consider renaming is_key_answer to is_model_solution for consistency.

The new column added to the Solution model is referred to as is_model_solution in the migration function but is named is_key_answer here. Aligning these names would improve code readability and maintainability.

suggestion (code_refinement): Ensure the return value of _add_is_model_solution_column is meaningful.

The function always returns True, which might not be informative. Consider returning a value that reflects whether the migration was necessary or successful.

issue (complexity): Consider abstracting the column addition into a more generic function.

While the added functionality in _add_is_model_solution_column achieves the intended migration task, it introduces a higher level of complexity and specificity to the migration module. This approach could potentially make the codebase harder to maintain, especially as more migrations are added over time. To streamline the migration process and adhere to the DRY principle, consider abstracting the column addition into a more generic function. For instance:

def _migrate_add_column(model, column_name, column_type):
    if not column_exists(model, column_name):
        with models.database.atomic():
            migrator = MySQLMigrator(models.database)
            migrate(
                migrator.add_column(model._meta.table_name, column_name, column_type())
            )
        log.info(f"Column {column_name} added to {model._meta.table_name}")
    else:
        log.info(f"Column {column_name} already exists in {model._meta.table_name}")

This method can then be used for adding any column to any model, reducing the need for specific functions for each migration task. It simplifies the migration process, making the codebase easier to maintain and extend in the future.