•  DAO/RDO/ADO

The DAO classes have the following advantages:

• Better performance in some cases, particularly when using Microsoft Jet (.MDB) databases.
• Compatibility with the ODBC classes and with Microsoft Access Basic and Microsoft Visual Basic.
• Access to validation rules.
• Ability to specify relations between tables.
• A richer data access model, with support for Data Definition Language (DDL) as well as Data Manipulation Language (DML).

By using RDO, you can:

• Create simple cursorless result sets, or more complex cursors.
• Run queries and process any number of result sets.
• Execute stored procedures that return result sets with or without output parameters and return values.
• Execute action queries that perform data manipulation or data definition operations.
• Limit the number of rows returned or processed.
• Monitor all of the messages and errors generated by the remote data source without compromising the executing query.
• Enable synchronous, asynchronous, or event-driven asynchronous processing so your application isn't blocked while lengthy queries are executed or the current row pointer is repositioned.

ODBC provides the first step toward overcoming this challenge by enabling applications to access relational databases. However, as developers and system architects want to include non-relational data sources and to work in environments such as the Internet, they encounter the dilemma of either developing their own data-access paradigms or working with application program interfaces (APIs) that are incompatible in the new environments. Microsoft® ActiveX® Data Objects (ADO) along with OLE DB solves this dilemma by providing a single model that works with all data sources in a variety of environments.

ADO provides consistent, high-performance access to data, whether you're creating a front-end database client or middle-tier business object using an application, tool, language, or even an Internet browser. ADO is the single data interface you need for developing 1- to n -tier client/server and Web-based, data-driven solutions.