Palm OS Programming With Satellite Forms (cont.)

Databases Are Its Strength

Satellite Forms is a complete SDK that was undoubtedly designed for business application development. It has support for many features, but its database functionality is second to none. Like many development tools, Satellite Forms stores data in a relational database using tables.

Relational databases are sometimes confusing to beginning programmers although most catch on pretty quickly. In a few words, relational databases store data in objects called tables. Each table contains a specific set of data such as Invoices and Customers. The tables are arranged similarly to a spreadsheet with rows and columns, and much like a spreadsheet, an invoice table might contain columns for Invoice Number, Date, and Purchase Order Number. Each row, or record, of the Invoice table contains information about an individual invoice.

What separates a relational database from a spreadsheet is the relation that a column from one table has with a column from another table. For example, the Invoice table that was mentioned in the previous paragraph might track customers who place an order. We could store the customer name directly in the Invoice table, but we would be forced to store it multiple times if a customer ordered multiple items. Instead, we can create a reference (called a foreign key) to the corresponding record of the Customers table, which saves a tremendous amount of space.

Space savings are not the only advantage to relational databases however. There is also much greater flexibility with performing a variety of tasks. For instance, when information such as a customer address changes, it is updated in a single place (the Customers table), instead of being replaced in every entry. The other tables that relate to it will relate to the new information. As a result, there is tremendous saving of space and time.

Once the tables have been designed, a Graphical User Interface (GUI pronounced "Gooey"), is developed that allows end-users to enter and manipulate the data in the tables through a set of controls and forms. If you have experience using PC tools like Microsoft Access or Visual Basic, you will get up to speed with Satellite Forms very quickly.

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