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();
 }
 } 
}