REALBasic: TDG, 2nd Edition

Chapter 22. Databases

The techniques described in Chapter 21 for storing and retrieving data kept in files on disk are fine for most purposes, but sometimes your data calls for the sort of structured storage and flexible access that only a database can achieve.

To see why, you need to know what a database is. In its simplest form, a database is merely data kept in the form of a table—a grid of rows and columns, where the information throughout any given column is of a single datatype. A relational database consists of more than one table, and REALbasic databases can be relational; but even a single-table (flat-file ) database can be very useful. In fact, even the simplest imaginable flat-file database—a two-column table—can be useful. Suppose your application uses a dictionary, a set of word-definition pairs. How will this information be stored as a file? How will you look up information in the file? How will you modify information in the file? These aren’t difficult problems to solve, to be sure; but with a database, they are solved for you. In this example, one column consists of words, another consists of definitions; every row is a word-definition pair. End of problem! REALbasic gives you the facilities to add word-definition pairs to the file, to delete word-definition pairs, to see whether a particular word is listed, to look up the definition for a given word, and so forth.

Actually, REALbasic lets you work with databases in two ways. First, it provides a native ...