java04_main.java

Indexing. Create 10 rows with random values in indexed column. Select all in order and print.

import java.sql.*;
import java.util.*;
 
public class java04_main {
 
/*
                                                    
     * EXAMPLE - java04 for JDBC
                                                    
     * When you run this example, a new database is created with a single table
                                                    
     * that has an index.  Ten rows are inserted in random order.
                                                    
     * Finally all the data is read from the database using the index to order
                                                    
     * the results.
                                                    
     * 
                                                    
     * Full documentation for RDM is available at http://docs.raima.com/rdm/
                                                    
     * 
                                                    
     * For simplicity this example utilizes basic exception handling
                                                    
     * but good programming practices would dictate that this occur in 
                                                    
     * a full application.
                                                    
     */
                                                    
public static void main(String[] args) throws SQLException  {
 
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;

                                                    
try
                                                    
        {
/* Create the connection with a simple connection string */
                                                    
            conn = DriverManager.getConnection("jdbc:raima:rdm://local");
            conn.setAutoCommit(true);

                                                    
            CreateDatabase(conn);

                                                    
/* Open the connection to the database */
                                                    
            stmt = conn.createStatement();

                                                    
            Random rand = new Random();

                                                    
/* Insert ten rows into the table with random data */
                                                    
for (int ii = 0; ii < 10; ii++)
            {
                stmt.executeUpdate("INSERT INTO IndTab VALUES " + (rand.nextInt() % 100));
            }

                                                    
/* Scan through all the existing rows using the index for order */
                                                    
            rs = stmt.executeQuery("SELECT id FROM IndTab order by id");
while (rs.next() != false)
            {
                System.out.println(rs.getInt(1));
            }
        }
catch (SQLException sqle)
        {
            sqle.printStackTrace();
        }
finally
                                                    
        {
if(rs != null)
                rs.close();
 
if(stmt != null)
                stmt.close();

                                                    
if(conn != null)
                conn.close();           
        }
    }

                                                    
private static void CreateDatabase(Connection conn)
    {
        Statement stmt = null;

                                                    
try
                                                    
        {
/* Create the example database */
                                                    
            stmt = conn.createStatement();
/* Since the database is created here, it cannot be created twice */
                                                    
try {
                stmt.executeUpdate("DROP DATABASE java04");
            } catch (SQLException sqle) {}

                                                    
            stmt.execute("CREATE DATABASE java04");
            stmt.execute("CREATE TABLE IndTab (id INTEGER PRIMARY KEY)");
            conn.commit();
            stmt.close();
            stmt = null;
        }
catch (SQLException sqle)
        {
            sqle.printStackTrace();
        }
    }       
}