Sunday, September 23, 2007

Creating Application Frameworks for Multiple Projects

Once you create one Access database project, you're likely to find another reason to build one. And with each one you create, you'll likely evolve your techniques and refine each new database. A few tips that have helped me in the past, that you don't often find in the MS Access books or help sites:

1) Create a reusable code library. Create an empty database that will serve as your code library. Create a VBA reference to that database in your new project database (open the VBA Editor, click on Tools...References, then locate your file using the Browse method). Then, for each generic function you create that might be used in more than one project, put it in your code library database. Why is this helpful? For one thing, as you improve the VBA functions in your code library, it becomes easier for each of the separate database projects you've created to use that improved code without updating each database. This is especially true if you deploy front-end databases to multiple users. You can place the code library database on a central file server, then reduce the amount of maintenance you need to do on each separate front-end copy.

2) Create a reusable application framework. That is, as you begin to build each latest and greatest database, you'll likely find they have commonalities you can begin to standardize. Whether it's menu design or a popup reminder form, you'll have items that you use over and over again. Those are the ones you'll want to put into a framework template (for lack of a better name). Then when you go to create your newest project, you've got n% of the project ready to go.

3) If you are creating a database for multiple users where each user has a separate front-end, consider placing important configuration data in the back-end database. Some configuration information you might store in a local table (user-level preferences as an example), whereas you will want to put configuration data in a remote linked table if you may need to change it remotely or want the configuration to be the same for all users. For example, the output location of reports, or a parameter that determines whether you want logging turned on or off on the front-end databases.

It was only after creating about 20 different database projects that I came to use this approach, and it saved a lot of time maintaining front-end database copies and starting a new database project. The lessons really served as the foundation for UI Builder, which is intended to give Access developers a ready-made framework to create their own projects so they can focus on important things like creating user-friendly forms and sound database architectures. But whether you use something like UI Builder or create one for yourself, creating a reusable framework is a must if you're going to develop lots of Access databases.

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