Learn Access 2003 VBA with The Smart Method

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www.LearnAccessVBA.com

Lesson 3-4: Understand the

Access object model

About object hierarchies

We have already seen how a Car object can contain other objects (such as

a windscreen object).

Objects can also contain object collections of similar objects. In the earlier

example the Car object had a collection of Wheel objects. The wheel

objects did not necessarily have the same properties—for example there

may have been wider tyres fitted on the rear wheels.

Object models express the concept of a hierarchy evident in May Louise

Cooper’s observation above. Each of her bugs is connected to another

bug higher up in the hierarchy.

The Car object model

Before considering the Access object model let’s consider the Car object

model that we’ve been discussing. Here it is:

A Car object contains a Windscreen object and a collection of Wheel

objects.

Greater bugs have little bugs

Upon their backs to bite ‘em

Little bugs have lesser bugs

And so on ad infinitum

May Louise Cooper, “Friendly Beetles", (1916)

Session3

Session Three: The Object-Orientated Paradigm

© 2007 The Smart Method Ltd

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Each wheel object contains a Rim object, and a Tyre object.

Each Rim object contains a collection of WheelNut objects.

The Access object model

The Access object model contains a little over fifty objects. We’re going to

ease you gently into the model by introducing new objects as we use

them during this course. We’ve already identified three of the most

important objects.

Here’s the object model as we know it so far :

Microsoft always name collections in the plural and single objects in the

singular. It is thus obvious that the Forms item in the above diagram is

actually a collection of Form objects.

From the object model above it is clear that :

One Application object may contain zero, one or more Form objects.

Each Form object may contain zero, one or more Control objects.

Microsoft’s object model diagram

If you type Access Object Model into the help dialog you’ll be able to view

the entire Access object model.

Microsoft use color coding to indicate collections of objects, and there’s a

few objects that you might not recognize, but from what you have

learned in this section, and your existing Access skills, you will be able to

understand the purpose of many of the objects.

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