There are two types of modules: standard modules and class modules. Standard modules are modules that contain procedures that are not associated with any particular object. Class modules are modules that are associated with a particular object. Class modules can be used either for form or report modules or for custom objects accessible throughout your VBA application. For example, form and report modules can contain code that corresponds to a particular form or report. An example of a form module is an event procedure, such as the click event for a control on a form. Since Access 97, class modules can also be created independently of a form or report to create a definition for a custom object. The current chapter will focus on standard modules and class modules that are associated with a form or report. Custom objects are discussed in detail in Chapter 4.
In general, it is a good programming practice to write most or all of your business logic and data access for the application in procedures that are contained in standard modules and keep the presentation logic in class modules associated with the form or report. This separation of code concept was briefly introduced in Chapter 1 in the architecture section.
One way to create a module is to select the Modules tab in the database window and click the New button. Another way to create a module is to select Insert Module. Let's now create a sample database with a form and a module ...