The DB Interface Module provides the classes you need for data manipulation, error handling, expression formation, database connection, and database portability. As discussed in Chapter 2, Design Overview, SourcePro DB uses a two-module architecture. The DB Interface Module encapsulates database operations and data manipulation, while each database-dependent DB Access Module connects to its related database to normalize its data types.

The DB Interface Module provides both a standard interface, which shields you from SQL, and an alternative interface called Open SQL, which allows you to directly execute SQL statements. For more information on the Open SQL interface, see Open SQL Classes, and Chapter 15, Using the Open SQL Classes. This chapter summarizes the different kinds of classes in the DB Interface Module.