• Login
• Become a member
• RSS
• Part of the TechTarget network

I am sure a lot of developers have had the need to connect to non-Oracle databases from within Oracle 8i. Unless Oracle has a transparent gateway for your non-Oracle database, this is not a very simple task. This tip demonstrates how to do exactly that in Oracle 8i.

This technique works only on versions 8i and above since it requires the Oracle JVM to be installed inside the database. We did our implementation for Progress and I have helped others use it with MS SQL Server. Ideally, it should work with any database that you can find a JDBC driver for. This tip has also been published on

Oracle Magazine's Web site.

We have a Progress database in our environment and needed to access data in this database from within an Oracle stored procedure. We utilized Oracle's Java stored procedure functionality to make this possible. Here are the steps:

1. We used Merant's JDBC driver for Progress. We loaded this driver into the Oracle database using loadjava as below:

   loadjava -u system/manager -resolve -resolver "((* PUBLIC) (* SYS) (* SYSTEM) (* -))" -grant PUBLIC -synonym slje.jar slje.jar 
   

   Please refer to the Oracle Java Tools Reference for documentation on the loadjava utility. We had to use (* -) to validate some of the classes in the jar file even though some references could not be resolved. This is typically OK if you are loading a commercially available jar file. We also granted everyone the ability to use the driver (grant option) and created a public synonym too (synonym option).
2. Next we wrote a Java program that would accept a SQL string to execute on our Progress database and display the results as below:

   import java.util.*; 
   import java.sql.*; 
   import java.lang.reflect.*; 
   import java.util.Date; 
   import java.io.*; 
   import intersolv.*; 
   
   public class execQuery 
   
   { 
   
   public static void doQuery(String sqlString, String db){ 
   
   // REGISTER DRIVER 
       try { 
         Driver d = 
   (Driver)Class.forName("intersolv.jdbc.sequelink.SequeLinkDriver").newInstance(); 
       } catch (Exception e) { 
         System.out.println(e); 
       } 
   
   // GET CONNECTION 
      Connection con = null; 
      String userName = "scott"; 
      String password = "tiger"; 
      try{ 
         if ( db.equals("Production") ) 
           con = 
   DriverManager.getConnection("jdbc:sequelink://seqllinkhost:5050/[Progress];
          Database=/u15/proddb -H prodmach -S proddbserv -U dbuser -P dbpass",userName,password); 
         else 
           con = 
   DriverManager.getConnection("jdbc:sequelink://seqllinkhost:5050/[Progress];
          Database=/u15/devdb -H devmach -S devdbserv -U dbuser -P dbpass",userName,password); 
      }catch(Exception e){ 
         System.out.println(e); 
      } 
   
   
    // CREATE STATEMENT 
      Statement stmt = null; 
      try { 
          stmt = con.createStatement(); 
      } catch (Exception e){ 
          System.out.println(e); 
      } 
   
    // EXECUTE QUERY 
      ResultSet results = null; 
      try { 
          results = stmt.executeQuery(sqlString); 
      } catch (Exception e){ 
          System.out.println(e); 
      } 
   // GET ALL RESULTS 
      StringBuffer buf = new StringBuffer(); 
      try { 
          ResultSetMetaData rsmd = results.getMetaData(); 
          int numCols = rsmd.getColumnCount(); 
          int i, rowcount = 0; 
   
          while (results.next()){ 
             for (i=1; i <= numCols; i++) { 
                 if (i > 1) buf.append(","); 
                 buf.append(results.getString(i)); 
             } 
             buf.append("n"); 
             rowcount++; 
         } 
         System.out.println(buf); 
         System.out.flush(); 
         results.close(); 
     } catch (Exception e) { 
         System.out.println(e); 
     } 
   
   // CLOSE RESULT SET 
     try { 
         results.close(); 
     } catch (Exception e){ 
         System.out.println(e); 
     } 
   // CLOSE STATEMENT 
     try { 
         stmt.close(); 
     } catch (Exception e) { 
         System.out.println(e); 
     } 
   // CLOSE CONNECTION 
     try { 
         con.close(); 
     } catch (Exception e) { 
         System.out.println(e); 
     } 
   
   } 
   } 
   

3. This Java code was then compiled:

   javac execQuery.java 
   

4. Next this code is also loaded into the Oracle database in Scott's schema as below:

    
   loadjava -u scott/tiger -resolve -resolver "((* PUBLIC) (* SYS) (* SYSTEM) (* -))" execQuery.class 
   

5. Next the Java stored procedure execQuery.doQuery needs to be published so it is accessible to SQL and PL/SQL as below:

   create or replace procedure do_Query(sqlString varchar2, db varchar2) 
        as language java name 'execQuery.doQuery(java.lang.String,java.lang.String)'; 
   / 
   

   We did not need to publish the JDBC driver because that is being used from with the Java code.
6. Now we execute the code via SQL*Plus:

   SQL> set serveroutput on 
   SQL> call dbms_java.set_output(10000); 
   
   Call completed. 
   
   SQL> begin 
     2    do_Query('select ename,dept from emp','Development'); 
     3  end; 
     4  / 
   Vishal Shah,IS 
   John Doe,Sales 
   Steve Mathews,Marketing 
   
   PL/SQL procedure successfully completed. 
   
   SQL> 
   

We used this technique with Progress. You should be able to use a similar technique with your non-Oracle RDBMS. Hope this helps!!

For More Information

• Feedback: E-mail the editor with your thoughts about this tip.
• More tips: Hundreds of free Oracle tips and scripts.
• Tip contest: Have an Oracle tip to offer your fellow DBAs and developers? The best tips submitted will receive a cool prize -- submit your tip today!
• Ask the Experts: Our SQL, database design, Oracle, SQL Server, DB2, metadata, and data warehousing gurus are waiting to answer your toughest questions.
• Forums: Ask your technical Oracle questions--or help out your peers by answering them--in our active forums.
• Best Web Links: Oracle tips, tutorials, and scripts from around the Web.

Join the conversationComment

Disclaimer: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.

All Rights Reserved,Copyright 2003 - 2013, TechTarget