Visual Basic Concepts

DAO Remote Data Access Using Jet

This section discusses DAO functionality when it is connected to the Jet engine. The Microsoft Jet database engine is a stand-alone database management system that is capable of both processing queries and routing queries to remote servers as needed. Accessing Jet through DAO adds to Microsoft Visual Basic’s ease of development by providing an object-oriented development paradigm and accessibility to data-aware bound controls.

By using the Data control, DAO, or Microsoft Access, you can create code that is virtually database-independent, because Jet automatically performs all syntax and data manipulation translations for you. For example, you can write an application that accesses different types of data sources without making reference to specific remote server features. These data sources could be Open Database Connectivity (ODBC) databases, such as Microsoft SQL Server; Index Sequential Access Method (ISAM) databases, such as Microsoft FoxPro, Paradox, or dBASE; or other Jet databases.

Unlike most stand-alone database engines, Jet can perform heterogeneous joins across several dissimilar databases. If you are working with departmental data stored in ISAM format, and need to merge it with data on a centralized server, this is an essential feature.