Microsoft Access 2010 Bible

551

CHAPTER

Using Access Data

Macros

IN THIS CHAPTER

Creating data macros

Understanding table events

Building macros

Understanding macro

limitations

A

major new feature in Access 2010 is the ability to add data macros to
your native Access tables. A data macro is logic you attach to a table
to enforce business rules at the table level. In some ways a data
macro is similar to a validation rule, except that a validation rule is rather
unintelligent. All a validation rule can do is display a message to the user.
Validation rules can’t modify data or determine whether corrective action is
needed. Data macros are specifically provided to allow you to manage data-
oriented activity at the table level.

Most often, data macros are used to enforce business rules — such as a value
can’t be less than some threshold — or to perform data transformation dur-
ing data entry. The real value of data macros is that they’re in effect wherever
the table’s data is used. For example, if a data macro is attached to the sales
table, any time the sales data is displayed on a form or report, the data macro
is at work, watching for changes to the data and automatically controlling
what happens to the table’s data.

On the CD-ROM
This chapter uses a database named Chapter15.accdb. If you haven’t already
copied it onto your machine from the CD, you’ll need to do so now. This data-
base contains the tables, forms, reports, and macros used in this chapter.

Introducing Data Macros

Beginning with Access 2007, macros have played a more significant role in
many Access applications. For a very long time, macros were considered the
poor cousin to VBA statements. Although in many ways VBA and macros