Washington, September 15-18, 1999 – London, November 21-24, 1999

Developing a Database Abstraction and a Persistent Object Manager (POM) with VB/ADO and SQL Server

Ash Rofail

Ash Rofail Ash is the Chief Architect at Best Software the industry leader in Client/Server and Web-based Corporate Resource Management solutions. Ash writes regularly for Visual Basic Programmers Journal and Enterprise Development magazines as well as speaks at several conferences such as VBits. Ash also teaches Client/Server and Web database programming classes at The George Washington University and is the author of the following books: Building N-Tier Applications with COM and VB6, Mastering COM/COM+ and Building Windows DNA applications with COM and UML.

Outline of Content

Structure of the meta-data

Ø        Formal explanation of seperation of schema from object definition

o         Schema changes

o         SQL generation and isolation

o         Target database platform changes

Ø        Entities, Attributes

Ø        POM Objects, Members

o         Member Types

Ø        One Member maps to one Entity-Attribute

Ø        One POM object can have members mapping to many entities

Ø        Definition and concept of Root Entity

What a single entity POM meta-data definition looks like

Ø        The mapping of POM members to entity attributes

Ø        Member types

Ø        Member Views

Ø        Structural definition - query

Ø        The POM object's PROGID

What use of a single entity POM object looks like

Ø        The global instance of CApolloPOM

Ø        The COIDObject

Ø        Creating

Ø        Editing

o         ReturnProp internals

Ø        Deleting

Ø        Conditions

CPOMObject & The POM Template

Ø        Location of the template

Ø        High level overview - containment of the object POM

Ø        Creating a new POM object

o         Adding business rules

o         The events and their uses

POMCollections

Ø        Overview - Uses and drawbacks

Ø        Creating

Ø        Using the For Each syntax

Ø        Updates at the object level

Ø        'Peeling' objects from collections

Ø        Adding objects to the collections

POMLists

Ø        Overview - Uses and drawbacks

Ø        Architecture

Ø        Creating

Ø        Adding objects - restrictions by object type

Ø        Updating the list - cautions

Schema side relationships

Ø        Directionality -  - Source and target

Ø        Explanation of different types and limitations of each

Ø        Different types of objects that can be created with them

Ø        Impact on requirements for POM object definition

Ø        Creating multi-entity POM objects

Ø        Editing multi-entity POM objects

Ø        Deleting multi-entity POM object - importance of root object

Object side relationships

Ø        Explanation of relationship structure and definition

o         How they're defined - member type

o         Special functionality of POM objects in relation

o         Cascading or restricted deletes

Ø        Use of Lists and Collections from an object - parent property

Advanced POM Object Design

Ø        Containment of detail classes

Ø        Full structure planning and design

Ø        Wiring instantiation

Ø        Wiring updates

Ø        Exposing detail objects to application developers

Late Activation

Ø        Provides

Ø        Definition

Ø        Usage

Ø        Limitations

POM Aggregation

Ø        Provides

Ø        Definition

Ø        Usage

Ø        Limitations

sp_POMObject

Ø        Provides

Ø        Definition

Ø        Usage

Ø        Limitations