Solution Guide for Migrating Oracle on UNIX to SQL Server - Willy .Net

258 Developing: Applications — <strong>Migrating</strong> Javadriver installed <strong>for</strong> SQL Server will install a driver jar file, which contains driverclasses <strong>for</strong> the database interaction. If the jar file is missing in the classpath, thenthe application will flag a 'class not found' exception.Based on the application's architecture, the CLASSPATH must be set. The syntaxof this setting can vary between applications, servlets, JSPs, EJBs, and applets.a. For applications run directly from the operating system prompt, make sure thatthe driver can be found in the system's CLASSPATH. This can be per<strong>for</strong>medby moving the file to its original location, which is already listed in theclasspath, or adding the driver's current location to the CLASSPATH.b. For applications run within the IDE, the driver classpath has to be set in thevendor's IDE classpath. Refer to your vendor’s IDE documentation.c. For servlets and JSPs run within a servlet/JSP engine such as Tomcat, theclasspath can be set in the vendor's classpath setup screens or by copying thedriver jar file into the LIB folder of the engine’s installation.d. For EJBs, the JDBC driver jar file should also be set in the EJB vendor'sclasspath.e. For applets that run within a Web browser, copy the JDBC driver jar to theWeb server root and specify the driver jar file in the applet’s HTML archive tab.The following HTML code example shows this option used on an applet tag.4. If the SQL statements passed to the JDBC methods use any <strong>Oracle</strong>-specificsyntax, then these items will need to be updated to reflect T-SQL syntax. Migrationof PL/SQL to T-SQL is covered in detail in Chapter 11, "Developing: Applications— <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL."5. The metadata in<strong>for</strong>mation returned by the metadata methods should refer toSQL Server and the new JDBC Driver.To discover in<strong>for</strong>mation about a database, a DatabaseMetaData object must beobtained. ResultSetMetaData provides in<strong>for</strong>mation about the ResultSet, such asnumber of columns returned, an individual column's suggested display size,column names, and column types. If any of these metadata are used in theapplication, they have to be validated <strong>for</strong> integrity of the return values.To discover in<strong>for</strong>mation about a database, a DatabaseMetaData object must beobtained. The getMetaData method on the Connection object returns aDatabaseMetaData object.DatabaseMetaData dbmd = con.getMetaData();ResultSetMetaData provides in<strong>for</strong>mation about the ResultSet. Use thegetMetaData method on the resultSet to get the ResultSetMetaData.ResultSetMetaData rsmd = rs.getMetaData();6. After the application changes are complete, create a new release build and fullytest the application.