1. 24/01/2011 harshana-fernando.blogspot.com 1 Introduction to Procedures Modules A module is a file that holds code or pieces of code in a Visual Basic application you can open the object in Design View and click the View Code button

2. 24/01/2011 harshana-fernando.blogspot.com 2 Creating a Module In Microsoft Access, on the Ribbon, click Create. In the Other section, click the arrow under the Macro button and click Module In Microsoft Visual Basic On the main menu, click Insert -> Module On the Standard toolbar, click the arrow of the Insert Module button and click Module

3. 24/01/2011 harshana-fernando.blogspot.com 3 Sub Procedures A procedure is an assignment you ask Microsoft Visual Basic to perform besides, or to complete, the normal flow of the program. A procedure is created to work in conjunction with the controls' events of a database. Structurally, a procedure appears similar to an event. Sub ProcedureName() End Sub Sub CreateName() Dim strFullName As String strFullName = "Jacques Fame Ndongo" End Sub

4. 24/01/2011 harshana-fernando.blogspot.com 4 Inserting a Procedure On the main menu, click Insert -> Procedure On the Standard toolbar, click the arrow of the Insert button and click Procedure

5. 24/01/2011 harshana-fernando.blogspot.com 5 Calling a Procedure Private Sub Detail_Click() ChangeColor End Sub Private Sub cmdSqCalculate_Click() SquareSolution End Sub Private Sub cmdRCalculate_Click() SolveRectangle End Sub

6. 24/01/2011 harshana-fernando.blogspot.com 6 Functions A function is a procedure that takes care of an assignment and returns a result. Function GetFullName() End Function Function GetFullName() As String End Function Function GetFullName() As String Dim strFirstName, strLastName As String strFirstName = txtFirstName strLastName = txtLastName GetFullName = strFirstName & " " & strLastName End Function

7. 24/01/2011 harshana-fernando.blogspot.com 7 Calling a Function Private Sub Detail_DblClick(Cancel As Integer) txtFullName = GetFullName End Sub Function GetFullName() As String Dim strFirstName, strLastName As String strFirstName = txtFirstName strLastName = txtLastName GetFullName = strFirstName & " " & strLastName End Function

8. 24/01/2011 harshana-fernando.blogspot.com 8 Introduction to Built-In Objects Microsoft Access heavily relies on built-in objects and already created collections. These collections are made in entities we call classes. Besides the collections and objects, there are also many enumerations. To display the Object Browser: On the main menu, click View -> Object Browser On the Standard toolbar, click the Object Browser button

9. 24/01/2011 harshana-fernando.blogspot.com 9

10. 24/01/2011 harshana-fernando.blogspot.com 10 The Current Project Private Sub Detail_Click() Dim CurrentDatabase As Object Set CurrentDatabase = Application.CurrentProject txtFilename = CurrentDatabase.FullName End Sub

11. 24/01/2011 harshana-fernando.blogspot.com 11 The DoCmd Object AddMenuApplyFilterBeepCancelEventClose CopyDatabas eFile CopyObjectDeleteObjectDoMenuItemEcho FindNextFindRecordGoToControlGoToPageGoToRecord HourglassMaximizeMinimizeMoveSize OpenDiagramOpenFormOpenFunctionOpenModuleOpenQuery OpenReport OpenStoredPr ocedure OpenTableOpenViewOutputTo PrintOutQuitRenameRepaintObjectRequery RestoreRunCommandRunMacroRunSQLSave SelectObjectSendObjectSetMenuItemSetWarnings ShowAllRecor ds ShowToolbar TransferDatab ase TransferSprea dsheet TransferSQLD atabase TransferText OpenDataAcc essPage

12. 24/01/2011 harshana-fernando.blogspot.com 12 Microsoft Access Object Library and VBA on the main menu of Microsoft Visual Basic, you can click Tools -> References...

13. 24/01/2011 harshana-fernando.blogspot.com 13 When you start a database in Microsoft Access, you are said to have started a session. If one database is not enough for what you are currently doing, you can open another existing database or you can create a new one.

14. 24/01/2011 harshana-fernando.blogspot.com 14 Microsoft Office 2007 ships with a library that can be used to perform all types of operations on a database and used throughout all applications of the Microsoft Office family. This library is called Microsoft Office Access Database Engine Object. Like every library, it has a version. In Microsoft Office 2007, it is the Microsoft Office 12.0 Access Database Engine Object Library.

15. 24/01/2011 harshana-fernando.blogspot.com 15 Using DAO If you decide to use the DAO library, you must remove the Microsoft Office 12.0 Access Database Engine Object Library because both libraries cannot coexist in the same database

16. 24/01/2011 harshana-fernando.blogspot.com 16 Microsoft ActiveX Data Objects- ADO

17. 24/01/2011 harshana-fernando.blogspot.com 17 Connection to a Database Private Sub cmdConnector_Click() Dim conConnector As ADODB.Connection Set conConnector = New ADODB.Connection Set conConnector = Nothing End Sub After using the Connection variable, to release the resources it using, assign Nothing to it.

18. 24/01/2011 harshana-fernando.blogspot.com 18 Opening a Connection Connection.Open ConnectionString, UserID, Password, Options The most common provider we will use is the Microsoft JET database engine. It is represented as Microsoft.JET.OLEDB.4.0 (case insensitive). You can use it to specify the provider as follows Private Sub cmdConnector_Click() Dim conConnector As ADODB.Connection Set conConnector = New ADODB.Connection conConnector.Open "Provider=Microsoft.Jet.OLEDB.4.0" Set conConnector = Nothing End Sub

19. 24/01/2011 harshana-fernando.blogspot.com 19 Private Sub cmdConnector_Click() Dim conConnector As ADODB.Connection Set conConnector = New ADODB.Connection conConnector.Open "Provider='Microsoft.Jet.OLEDB.4.0';" & _ "Data Source=C:\Exercises\Example.accdb" Set conConnector = Nothing End Sub

20. 24/01/2011 harshana-fernando.blogspot.com 20 Connection to the Current Database Private Sub cmdCurrentConnection_Click() Dim conCurrent As ADODB.Connection Set conCurrent = Application.CurrentProject.Connection Set conCurrent = Nothing End Sub When this code executes, it identifies the connection to the current database and stores it in a declared variable named conCurrent

21. 24/01/2011 harshana-fernando.blogspot.com 21 Closing a Connection Private Sub cmdDataSource_Click() Dim conConnector As ADODB.Connection Set conConnector = New ADODB.Connection conConnector.Open "DSN=Exercise;UID=;PWD=;" conConnector.Close Set conConnector = Nothing End Sub When using a connection, it consumes resources that other applications may need. Therefore, after using it, you should close it and free the resources it was using so they can be made available to the other parts of the computer

22. 24/01/2011 harshana-fernando.blogspot.com 22 Table Creation With the Microsoft Access Object Library Private Sub cmdCreateTable_Click() Dim curDatabase As Object Dim tblStudents As Object ‘ Get a reference to the current database Set curDatabase = CurrentDb ' Create a new table named Students Set tblStudents = curDatabase.CreateTableDef("Students")... ' Add the Students table to the current database curDatabase.TableDefs.Append tblStudents End Sub After creating the table, you must add it to the current database. To support this, the CurrentDb object is equipped with the TableDefs property. TableDefs is in fact a collection. The TableDefs collection is equipped with the Append() method that is used to add a new table to the current database.

23. 24/01/2011 harshana-fernando.blogspot.com 23 Table Creation With DAO Private Sub cmdCreateTable_Click() Dim dbDeja As DAO.Database Dim tblEmployees As DAO.TableDef ' Open the database Set dbDeja = DBEngine.OpenDatabase("C:\My Documents\Exercise.accdb") ' Create a new TableDef object. Set tblEmployees = dbDeja.CreateTableDef("Employees")... ' Add the new table to the database. dbDeja.TableDefs.Append tblEmployees dbDeja.Close End Sub