ADO: ActiveX Data Objects

Accessing ADO with Visual Basic

Visual Basic is probably the most popular language in which to develop applications for ADO. It is also the language used in the examples and code throughout this book. Visual Basic is a very easy language to understand and excellent for both beginners and advanced developers.

Referencing ActiveX Data Objects

To write an application in Visual Basic using ActiveX Data Objects, you must first tell Visual Basic about them by adding ADO to the list of references that Visual Basic uses to run an application. You may do this by selecting the Project → References menu item so that the References dialog box appears, as shown in Figure 3-1. In the Available References list box, select the latest version of Microsoft ActiveX Data Objects Library that you have installed. Now you are ready to create and use ADO objects within your current Visual Basic application.

Figure 3-1. The References dialog box of Visual Basic

When redistributing ADO applications, you should use the MDAC redistributable package available for download from Microsoft’s web site.

Creating ActiveX Data Objects

In Visual Basic, you can create new ADO objects by simply referencing the ADODB classes of the Microsoft ActiveX Data Objects Library. The following piece of code creates a Connection and a Recordset object in Visual Basic:

' create a reference to a Connection object Dim con As ADODB.Connection ...