008.module

Automating Tasks with
Visual Basic

Introduction
 When can’t find a readymade macro action that
does the job you want, you can use Visual Basic
code.
 Example:
− Modify a whole batch of records at once.
− Perform complex calculations.
− Interact with other programs on computer.
− Write even more complicated validation
routines that lock out bad data.

Understanding VBA Terminology
 Some basic VBA terminology:
− Statement: A word or combination of words
that constitutes an instruction to be
performed by the VBA engine.
− Procedure: A collection of VBA statements
that are grouped together to perform a certain
task. There are two types of procedures:
 Subroutines: perform a single task, no
return.
 Functions: perform a task and then return a
value

Understanding VBA Terminology
− Module: Procedures live in modules. A
module consists of one or more procedures
− Variable: is nothing more than a name
applied to represent a data value. Variable is
used to hold values such as customer
names, dates, and numeric values
manipulated by the VBA code.

The Visual Basic Editor
 Visual Basic code is stored in database, but it
need a different tool to view and edit it, called
the Visual Basic editor.
 Open the Visual Basic editor:
 In the Access ribbon, choose Database
Tools➝ Macro ➝ Visual Basic

The Visual Basic Editor
 The Visual Basic editor window is divided into
three main regions.
− Project window: shows all the modules in
your database.
− Properties window: which shows settings for
the currently selected item in the Project
window.
− Document window: Edit code region.

Adding a New Module
 In the Visual Basic editor’s menu, choose Insert
➝ Module.

Adding a New Module
 When add a new module, the Visual Basic
editor automatically opens a code window that
shows the contents of that module.
 Initially, a brand-new module has just one line
of code:
Option Compare Database
− This line is an instruction that tells Visual
Basic how to handle operations that compare
pieces of text.

Adding a New Module
 Before write code you should add one more
instruction to the top of code file:
Option Explicit
 This instruction tells Visual Basic to use stricter
error checking, which catches common typos
when using variables.

Simplest Possible Code Routine
 Every module are one or more subroutines. A
subroutine is a named unit of code that
performs a distinct task.
 Subroutines start with the word Sub followed
by the name of the subroutine and end with the
statement End Sub
 Example:
Sub MyCodeRoutine()
MsgBox "Witness the power of my code."
End Sub

Module types
 Access stores code in two places:
− Class modules: attached to the form or
report, it executes when the form or report is
opened, the class module does not appear in
the modules section.
− Standard modules: Code can also be stored
in modules section. Standard modules is
accessible to all objects in your database.

Responding to a Form Event
 Open a form in Design mode.
 Turn off Control wizard button.
 Add a new button.
 In the Property Sheet, choose the Event
tab, and then select the button’s On Click
event
 Click the ellipsis (…) in the On Click Event box
 Select Code Builder and click OK

008.module

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008.module