// -----------------------------------------------------------------------------
// QueryExample.java
// -----------------------------------------------------------------------------

/*
 * =============================================================================
 * Copyright (c) 1998-2007 Jeffrey M. Hunter. All rights reserved.
 * 
 * All source code and material located at the Internet address of
 * http://www.idevelopment.info is the copyright of Jeffrey M. Hunter and
 * is protected under copyright laws of the United States. This source code may
 * not be hosted on any other site without my express, prior, written
 * permission. Application to host any of the material elsewhere can be made by
 * contacting me at jhunter@idevelopment.info.
 *
 * I have made every effort and taken great care in making sure that the source
 * code and other content included on my web site is technically accurate, but I
 * disclaim any and all responsibility for any loss, damage or destruction of
 * data or any other property which may arise from relying on it. I will in no
 * case be liable for any monetary damages arising from such loss, damage or
 * destruction.
 * 
 * As with any code, ensure to test this code in a development environment 
 * before attempting to run it in production.
 * =============================================================================
 */
 
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * -----------------------------------------------------------------------------
 * The following class provides an example of using JDBC to perform a simple
 * query from an Oracle database.
 * 
 * @version 1.0
 * @author  Jeffrey M. Hunter  (jhunter@idevelopment.info)
 * @author  http://www.idevelopment.info
 * -----------------------------------------------------------------------------
 */

public class QueryExample {

    final static String driverClass    = "oracle.jdbc.driver.OracleDriver";
    final static String connectionURL  = "jdbc:oracle:thin:@localhost:1521:O920NT";
    final static String userID         = "scott";
    final static String userPassword   = "tiger";
    Connection   con                   = null;


    /**
     * Construct a QueryExample object. This constructor will create an Oracle
     * database connection.
     */
    public QueryExample() {

        try {

            System.out.print("  Loading JDBC Driver  -> " + driverClass + "\n");
            Class.forName(driverClass).newInstance();

            System.out.print("  Connecting to        -> " + connectionURL + "\n");
            this.con = DriverManager.getConnection(connectionURL, userID, userPassword);
            System.out.print("  Connected as         -> " + userID + "\n");

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }

    }


    /**
     * Method to perform a simply query from the "emp" table.
     */
    public void performQuery() {

        Statement stmt      = null;
        ResultSet rset      = null;
        String queryString  = "SELECT name, date_of_hire, monthly_salary " +
                              "FROM   emp " +
                              "ORDER BY name";

        try {

            System.out.print("  Creating Statement...\n");
            stmt = con.createStatement ();

            System.out.print("  Opening ResultsSet...\n");
            rset = stmt.executeQuery(queryString);

            int counter = 0;
            
            while (rset.next()) {
                System.out.println();
                System.out.println("  Row [" + ++counter + "]");
                System.out.println("  ---------------------");
                System.out.println("      Name             -> " + rset.getString(1));
                System.out.println("      Date of Hire     -> " + rset.getString(2));
                System.out.println("      Monthly Salary   -> " + rset.getFloat(3));
            }

            System.out.println();
            System.out.print("  Closing ResultSet...\n");
            rset.close();

            System.out.print("  Closing Statement...\n");
            stmt.close();

        } catch (SQLException e) {

            e.printStackTrace();

        }

    }


    /**
     * Close down Oracle connection.
     */
    public void closeConnection() {

        try {
            System.out.print("  Closing Connection...\n");
            con.close();
            
        } catch (SQLException e) {
        
            e.printStackTrace();
            
        }

    }


    /**
     * Sole entry point to the class and application.
     * @param args Array of String arguments.
     * @exception java.lang.InterruptedException
     *            Thrown from the Thread class.
     */
    public static void main(String[] args)
            throws java.lang.InterruptedException {

        QueryExample qe = new QueryExample();
        qe.performQuery();
        qe.closeConnection();

    }

}