+ def from_table_row(cls: type[BaseModelInstance],
+ # pylint: disable=unused-argument
+ db_conn: DatabaseConnection,
+ row: Row | list[Any]) -> BaseModelInstance:
+ """Make from DB row, write to DB cache."""
+ obj = cls(*row)
+ obj.cache()
+ return obj
+
+ @classmethod
+ def _by_id(cls, db_conn: DatabaseConnection,
+ id_: BaseModelId) -> Self | None:
+ """Return instance found by ID, or None, and if from cache or not."""
+ obj = cls.get_cached(id_)
+ if not obj:
+ for row in db_conn.row_where(cls.table_name, 'id', id_):
+ obj = cls.from_table_row(db_conn, row)
+ obj.cache()
+ break
+ return obj
+
+ @classmethod
+ def by_id(cls, db_conn: DatabaseConnection,
+ id_: BaseModelId | None,
+ # pylint: disable=unused-argument
+ create: bool = False) -> Self:
+ """Retrieve by id_, on failure throw NotFoundException."""
+ obj = None
+ if id_ is not None:
+ obj = cls._by_id(db_conn, id_)
+ if obj:
+ return obj
+ if create:
+ obj = cls(id_)
+ return obj
+ raise NotFoundException(f'found no object of ID {id_}')