.. change::
    :tags: bug, orm
    :tickets: 9537

    Expanded the warning emitted when a plain :func:`_sql.column` object is
    present in a Declarative mapping to include any arbitrary SQL expression
    that is not declared within an appropriate property type such as
    :func:`_orm.column_property`, :func:`_orm.deferred`, etc. These attributes
    are otherwise not mapped at all and remain unchanged within the class
    dictionary. As it seems likely that such an expression is usually not
    what's intended, this case now warns for all such otherwise ignored
    expressions, rather than just the :func:`_sql.column` case.
