Personal Oracle Light (POL) FAQ

$Date: 10-Nov-1998 $
$Revision: 1.0 $
$Author: Frank Naudé $

Topics

• POL runs in under 1 megabyte of memory, and can be installed in 3 megabytes of hard disk space;

• has full Java and SQL support (no PL/SQL);

• is ODBC and JDBC compliant;

• can handle up to 16 concurrent application connections;

• supports replication via file, HTTP, SQL*Net, and Oracle Mobile Agents;

• runs on WindowsNT, Windows95/98, WindowsCE, and PalmOS.

• PL/SQL (use Java Stored Procedures and triggers instead)

• Oracle Light is intended as a small, single-user client database and do not support any server functionalities like Java CORBA ORB's, SQL*Net Listeners, etc.

• In Oracle Lite, all rows are stored as objects, and there is a relational layer on top of the object layer to allow relational views of the data. Oracle7/8 stores data in a relational format, then uses an object metalayer to provide object views and functionality.

• Only selected dictionary views are available, eg. ALL_TABLES, ALL_VIEWS, ALL_USERS, CAT, etc.

• An Oracle Lite database can only be queried from a remote client if it's data is replicated.

The following command line is used to access the default starter database via SQL*Plus:

plus33 system/manager@odbc:polite:polite
SQL> select * from all_tables;
SQL> exit;

In this example we will create a Java class "EMPL" in a file called EMPL.java to implement the get_sal method:

import java.sql.*;

public class EMPL {

  public static int get_sal(Connection conn, int empno) throws Exception
  {
     Statement s = conn.createStatement();
     ResultSet r = s.executeQuery("SELECT sal, nvl(comm,0) FROM EMP WHERE empno="+empno);
     int     sal = 0;

     if (r.next()) {
        sal = r.getInt(1) + r.getInt(2);   /* sal = :sal + :comm */
     } else {
        throw new Exception("Employee "+empno+" is invalid.");
     }

     r.close();  s.close();
     System.out.println("Salary for employee "+empno+" is "+sal);
     return sal;
  }
}

Step 2: Attach the Java Class to the Table

ALTER TABLE EMP ATTACH SOURCE "EMPL" IN '.';

Step 3: Execute the Method

To execute the get_sal method from SQL*Plus:

SELECT EMP."get_sal"(7369) FROM DUAL;

To execute this method from ODBC:

SQLExecDirect(hstm, "SELECT EMP.\"get_sal\"(7369) FROM DUAL");

• Use the ODBC function to get the DB name: SELECT CAST({FN DATABASE()} AS CHAR(16)) FROM DUAL;

• To create a new database use the following command line: CREATEDB polite new_db_name

• Connect to your newly created DB with connect string: system/manager@odbc:polite:new_db_name

• Oracle's POL pages