automatic tasks with visual basic

 When can’t find a readymade macro action that does the job you want, you can use Visual Basic code.. Understanding VBA Terminology Some basic VBA terminology: − Statement: A word or

Automating Tasks with

Visual Basic

 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