Tables Are the Center of the Access Universe


I want to start by re-emphasizing the primacy of tables, not just relative to forms, but to all other Access objects as well. The Database window does not make the essential role of tables clear; the positioning of the buttons makes it seem that tables are merely first among equals (see Figure 6.1). A graphic representation of Access objects that conveyed their relative significance would look more like the solar system. The tables are at the center of the universe; they are, so to speak, the sun. All other objects are planets that merely revolve around tables.

Figure 6.1. In the Database window, tables appear merely as the first of equals rather than as the cornerstones of your database that they truly are.


You can make forms that present your data beautifully onscreen, create exquisite queries that retrieve exactly the information you need, and design reports that powerfully communicate your data to external audiences. But ultimately, all of these are merely manipulations of the data stored in tables. Similarly, you can enter and edit data in tables, forms, or queries (although not in reports). But the ultimate effect of all your work is to delete, add, or alter records stored in the underlying tables.

The upshot is that, if you want to add the value celery sticks to your database, or change celery sticks to stuffed olives, it doesn't matter whether you do it in a table, form, or query. Whatever changes you make to values in these objects are immediately reflected in the table that stores the field where celery sticks and stuffed olives reside.

Let me reinforce the concept of table primacy with one more example. Let's say you create a form from a table. You immediately add two records and close the form. Later that day, you delete the form. Those records you added to the form remain in the underlying table. And the exact same scenario holds true when you add records to a query.

On the other hand, what happens if you delete the table that is the source for the form or query? The form and query physically remain in your database; but they are essentially empty shells because their underlying foundation has been hacked away. Put more metaphorically, they become like Japanese ronin, Japanese samurai who lost their masters. Without a lord to serve, their lives became purposeless, and the samurai code required that they commit suicide. Although tableless forms are under no such ethical requirement, they are equally doomed.

NOTE

Some forms exist independently of any table. These are exceptions, however, and the previous discussion applies to most of the forms you'll work with.





Hands-On Microsoft Access(c) A Practical Guide to Improving Your Access Skills
Hands-On Microsoft Access: A Practical Guide to Improving Your Access Skills
ISBN: 0321245458
EAN: 2147483647
Year: 2005
Pages: 169
Authors: Bob Schneider

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net