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

Alfredo Novoa wrote:
> Robert Martin wrote:
>
>

>>>>The big problem with OO and RDB is that people try to make them
>>>>represent each other.  RDB is about data structure an OO is about
>>>
>>>behavior structure.

>>>No no no! RDB is about data management and OO is about application
>>>programming.

>>That's what I said.  This shows profound ignorance of Thesauri.

>>>The DBMS must enforce all the business rules (data behavior). The OO
>>>applications must enforce the presentation and communication behavior.

>>Nahhh.  The DBMS must store the data, manage the queries, and enforce
>>some integrity rules.  Business rules are in the domain of the
>>application.  We don't want the business rules being done by the
>>database.  What if we replace the database vendor?  Must we rewrite all
>>the business rules?

>>>>The objects in the OO program should MANIPULATE the
>>>>data structures from the RDB.

>>>Very wrong. The OO program should TRANSFORM the user input in orders
>>>for the DBMS.

>>>The OO program is an interface between the users and the DBMS. A
>>>friendly substitute for the DBMS console.

>>No, a DBMS is a bucket of bits with some low level rules to manage
>>those bits.  An OO application provides the beavior that the customer
>>wants to see.  We can completely eliminate the DBMS and replace it with
>>another of an entirely different form (non Relational for example) and
>>still have all the business behavior we need.

>>The people who sell databases have sold you, and the industry, a
>>misconception: that the database is the heart of the system.  This is
>>flawed.  The heart of the system is the application code.  The database
>>is a detail to be decided at the last possible moment and kept in a
>>position so flexible that it can be swapped out for another at a whim.

Hm, I take it you're not a big fan of the Active Record pattern?

Joe Received on Wed May 31 2006 - 00:04:05 CEST