Database macro programming has changed enormously over the last 15 years, having gone from Access Basic macros to VBA. Another major change occurred with Office 95, when macros went to VBA modules in a separate environment accessed via the Visual Basic Editor. It used to be fairly basic: code was entered into a special design window. Although the language was rather powerful in its own right, it was not a structured language and could certainly not be described as object-oriented.
The number of commands was limited, and a fair amount of ingenuity was required to do certain tasks. The main advantage was that it was fairly easy to learn and understand; many programmers cut their teeth by initially writing database macros. If anyone other than the original author examined the code, it could take days to find out exactly how it worked and what it was doing.
Commercial companies frequently found that when the author of a complicated macro left the company, that macro had to be rewritten from scratch because of the time involved in assessing what it was doing. Microsoft has introduced a new programming language called Visual Basic for Applications (VBA). VBA is a more intuitive and robust programming language, using an object-oriented design. It has many similarities with its older and larger cousin, Visual Basic (VB). Once you learn VBA, you will have a fair understanding of how Visual Basic itself operates. VBA is extremely different from the old macro language, and if the older language is what you are used to, it will mean totally rethinking how you write and structure your code.
The concepts of object-oriented programming (OOP) are as different as chalk and cheese to the old macro language, but there is a huge advantage in terms of what you can achieve on a spreadsheet. With object-oriented programming, you are dealing with the concept of objects. To use an example, the database you load is an object.
The tables and queries where you access your data are other objects, and so are the printer and the screen. They have properties, events, and methods (discussed later in the book). You will start to see object-oriented programming in more detail when you reach Chapter 14. VBA does allow a more structured and object-oriented approach to writing your macros. If this is your first foray into the world of Access macro programming, you may well find the concepts easier to grasp, since you have no knowledge of the technologies used in the past within Excel.
The Access Basic macros were a completely different language in terms of how
and where you entered it. The concept of VBA is unique and cannot be compared to the old
Access Basic macros. Unfortunately, knowledge of the old system of writing macros can add
to confusion with the new method of VBA and extend the learning curve
