Re: The wisdom of the object mentors (Was: Searching OO Associations with RDBMS Persistence Models)

On Thu, 1 Jun 2006 14:01:18 +0300, x wrote:

> "Dmitry A. Kazakov" <mailbox_at_dmitry-kazakov.de> wrote in message
> news:1lrornqlsngid.1g1itr3c2tr04$.dlg_at_40tude.net...

>> On 1 Jun 2006 02:58:43 -0700, Erwin wrote:

>>>
>>> Note further that the OO crowd always uses the term with respect to one
>>> single thing ("the identity of an object").
>>
>> This is not true. As for identity of objects there are many of. For
>> example, polymorphic objects have the identity of its specific type. The
>> identity of objects in its usual sense is not required in OO. It is quite
>> possible to have unidentifiable objects.

Yes, if the fly! (:-))

>>> The OO crowd thus never uses that term in the "relational" sense of the
>>> word.

>> I don't see much difference in respect of identity. The standpoint is that
>> there is no data, only behavior.

>> Data is expressed in observed behavior.

How do you change data, what is the effect of a change? Both are specified in operations. Let you have changed the data, but the effect of all operations you could apply to, is same as before. How can you determine if you really did? What if I reverted your change while you looked aside. Can you catch me?

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de