Open Database Access and ODBC (3)

What is ODBC?

ODBC is a standardized API (Application Programming Interface). It is a set of function calls based on the SQL Access Group (SAG) function set for utilizing a SQL database system (back-end system). The SAG set implements the basic functionality of Dynamic SQL. Embedded SQL commands can be translated to call ODBC.

With ODBC, Microsoft extended the basic SAG function set to include functions for accessing the database catalog and for controlling and determining the capabilities of ODBC drivers and their data sources (back-ends). They also have refined and fleshed out the SAG proposal. Microsoft supplies the ODBC Driver Manager for their operating systems (Windows, Windows 95, Windows NT). The ODBC Driver Manager coordinates access to ODBC drivers and their associated data sources.

ODBC Architecture

Applications access ODBC functions through the ODBC Driver Manager which dynamically links to the appropriate ODBC driver. ODBC drivers translate ODBC requests to native format for a specific data source. The data source may be a complete RDBMS like FirstSQL or it may be a simple file format, like Xbase.

Most ODBC drivers are tied to a single data source. Some, like FirstSQL, support multiple data sources. The FirstSQL ODBC driver supports both a FirstSQL data source and an Xbase data source.

ODBC Utilization

ODBC provides a robust set of functions for access to a database. The interface is complicated and takes time to learn to use well. It is often layered with a higher level interface like Embedded SQL, C++ classes or Visual Basic controls. Another example of higher level interfaces is Microsoft's OLE DB.

Though often accessed through higher level objects, ODBC provides the appropriate power to utilize databases. It is the most widely supported portable database interface available. But, a shadow has been cast over The Future of ODBC by the actions of Microsoft.

Return to Contents Page: Open Database Access and ODBC Return to Issues Page