How do data access APIs work?
Monolithic applications integrated presentation logic, business rules and data access logic. Today we are distributing logic across clients and servers by using middleware and other tools. We are also using Extensible Markup Language (XML) as both a publishing and data integration technology. This roadmap explains how data access technologies fit into the picture of client-server, Web, grids and distributed computing.
Open Database Connectivity (ODBC)
Open Database Connectivity (ODBC) is an application programming interface (API) for programs that use SQL to access data. ODBC is a multi-database API because an ODBC program can operate with heterogeneous databases and disparate SQL DBMSs without requiring source code changes. Microsoft created ODBC by extending a Call Level Interface from the SQL Access Group (now part of The Open Group). The American National Standards Institute and International Standards Organization adopted an SQL/CLI as part of the SQL-92 standard. ODBC 3.x aligns with that standard. There are ODBC implementations for several operating systems including Linux and Unix.
The ODBC portal consolidates links to drivers, published articles, facts and myths, benchmark results, and the ODBC Hall of Fame.
Conferences such as DB/Expo, Object-Relational Summit, Database Expo (UK), UnixExpo and Database and Client Server World featured Data Access Workshops. They featured expert panels with gurus from Microsoft, Sun, OpenLink Software, NCR Teradata and other organizations (view workshop presentations).
JDBC™ is an SQL API for Java programs (servlets, applications, applets). JDBC uses SQL queries and provides Java classes that abstract the data access process. Sun's Java Software includes JDBC as part of the standard Java APIs. Developers can use Java and JDBC to program all tiers of a database application and to develop server-side extensions to SQL databases. JDBC is supported by providers who offer Java-enabled databases, also know as "Java in the database." Java-enabled databases reside on servers that use an internal JDBC driver for executing server-side JDBC programs.
JDBC documentation and software are at Sun's JDBC page. For information about JDBC 2.0, read "The Ascendancy of Java Data Access". JDBC 3.0 aligned more with SQL:99 and added support for RowSets and WebRowSets.
The web includes numerous articles about JDBC. Browse to the Java database portal for a list of articles about JDBC, SQLJ, Java, and databases. Check also the annotated list of Ken North's articles and white papers. Rich Katz also maintains an excellent Web page of Java database resource information. Another source of valuable information about JDBC and Java database programming is the JavaOne conference.
ADO.NET, ADO, OLE DB
Since aligning ODBC with the SQL Call-Level Interface in 1995, Microsoft has sponsored development of several data access APIs. These include OLE DB, Data Access Objects (DAO), Remote Data Objects (RDO), ActiveX Data Objects (ADO), and ADO.NET. DAO and RDO are deprecated APIs. Microsoft released OLE DB and ADO for the Windows platform and ADO.NET for .NET.
OLE DB and ADO support SQL commands for querying SQL databases, and MDX queries for querying multidimensional data. They also support rowset navigation for working with data sources, such as ISAM record managers, that do not expose a command-driven interface.
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This page was last updated on 07-Oct-2007.