How the SAS/SHARE^® Driver for JDBC Works

With the SAS/SHARE driver for JDBC, you can interactively view and update SAS data or any other data that is accessible through a SAS/SHARE server. The following diagram shows how an applet created using the SAS/SHARE driver for JDBC communicates with a SAS/SHARE server:

The Web browser on the client machine requests an HTML document from the Web server. The server responds by sending the document to the browser. If the browser detects an applet tag in the document, it sends additional requests to the Web server for the Java classes used by the applet. After the classes are downloaded to the client machine, the applet begins running.

The applet uses the JDBC driver classes to establish a connection to the SAS/SHARE server. After the connection is established, the driver provides SQL (Structured Query Language) access to the SAS/SHARE server. The applet can send SQL statements to the server and retrieve the results generated by those statements.

The SAS/SHARE driver for JDBC supports the SQL statement SELECT to obtain data as well as the SQL statements CREATE, UPDATE, INSERT, and DELETE to modify data. The results for an SQL SELECT statement are the set of rows and columns specified by that statement. The result of an SQL UPDATE statement is the number of rows modified by that statement.

The JDBC driver classes accept a URL that identifies the SAS/SHARE server. The URL is of the form jdbc:sharenet://hostname:portnumber. Hostname is the name of the machine where the SAS/SHARE server is running and portnumber is the port the SAS/SHARE server is configured to use.

By default, the JDBC classes use socket-based communication with the SAS/SHARE server. Socket communication with applets can be restricted by the Java security manager. The security manager is provided by the browser, and each browser has a different set of restrictions imposed on applets. Most security managers restrict socket-based communication and only allow applets to open socket connections to the same machine that provided the applet classes. This means the SAS/SHARE server and the Web server that provides the Java classes must run on the same machine. The tunnel feature eliminates this restriction, enabling you to install your Web server and your SAS/SHARE server on different machines.

For more information about the JDBC API specification as provided by Sun Microsystems, visit the JDBC page.