Datasheet

Designing Applications

Choosing a Storage Engine

Another choice which developers of Access 2002 applications will now need to make is which

database engine they will use to store the application's data in. Traditionally, Microsoft Access

has always used JET as its native database engine. Additionally, however, Access developers

are offered the choice of using a second desktop database engine, the Microsoft SQL Server

2000 Desktop Engine (henceforth MSDE).

To keep this chapter concise and to the point, we have placed the discussion of which storage

engine to use in Chapter 20. It is also worth reiterating at this point that the purpose of this

book is to teach how to use VBA in Access and for that reason all of the data access examples

will be against JET databases.

Entering and Viewing Data

So far, we've considered the need for careful analysis and table design. But that's only the start.

Now we have to consider how the users of our system are going to enter information into the

tables. Of course, they could type information straight into the tables in datasheet mode, but

that would be inelegant and inefficient, and would make it difficult to check data entry

properly. There may also be security issues involved as it is unlikely that we will want all the

users to be able to access sensitive data and this is impossible to achieve if the users have access

to the "raw" data tables. We therefore need to put an acceptable face on our application and

shield the users from the complexity of the table structure.

Designing a Form

The simplest way to create a quick-and-easy form is to use one of the Form Wizards. Using a

wizard to produce a form will give you all the fields you require from one or more tables. This

is great, but sometimes you'll need to add extra functionality to the form, in which case you'll

have to make any additional modifications yourself. We're going to use a Form Wizard to

create one of the key forms in the application – the form for maintaining company information.

Try It Out Creating a Form Using the AutoForm Wizard

As we explained in the Introduction, your starting point for the Try It Out

sections in this book is the IceCream.mdb database, found on the CD-ROM.

We have also included on the CD partially completed databases that reflect

each chapter's development, in case you lose your own copy, or want to jump

in at a later chapter. The databases are numbered such that they correspond

to the state at the end of a chapter – in other words, IceCream03 is the

database you'd get when you'd worked through to the end of Chapter 3. We

think it's better if you work through all of the Try It Outs, though, so you

can really get a feel for how everything works and fits together.