/*
I. Getting ready:


Once :
- A database program is installed (We work here with Oracle database), 
- The ORACLE_HOME path is set 
(ORACLE_HOME C:\oraclexe\app\oracle\product\10.2.0\server), 
- The correct related driver jdbc (here: ojdbc14.jar) 
is downloaded and its CLASSPATH is set 
(C:\oraclexe\app\oracle\product\10.2.0\server\jdbc\lib\ojdbc14.jar;); 
The complete classpath looks like:
The related classpath is then:
CLASSPATH =.;C:\Program Files\Java\jre1.5.0_14\lib\ext\dnsns.jar;
C:\Program Files\Apache Software Foundation\Tomcat 6.0\lib\servletapi.jar;
C:\oraclexe\app\oracle\product\10.2.0\server\jdbc\lib\ojdbc14.jar;
C:\oraclexe\app\oracle\product\10.2.0\server\jlib\orai18n.jar
- The http port is set at 1521:
From SQL command line:
SQL> -- set http port and ftp port
SQL>  begin
  2  dbms_xdb.sethttpport ('1521');
  3  dbms_xdb.setftpport ('1520');
  4  end;
  5  /
SQL> quit
- A table is created and completed,
we can start connecting to the databse, sending requests, and 
getting results via Java code.


II. Test the connectivity:
*/
	import java.sql.*;
	import oracle.jdbc.*;
	import oracle.jdbc.OracleDriver;

	public class OracleConnect
	{
	public static void main(String[] args)throws SQLException
	{
	try
	{
	Class.forName("oracle.jdbc.driver.OracleDriver");	
	 Connection conn = DriverManager.getConnection("jdbc:oracle:
	thin:@HOST:1521:XE","User","Password");
	if(conn != null)
	{ System.out.println("I am Connected to oracle database");
	}
	conn.close();
	} catch (Exception e) {
	System.out.println("ERROR : " + e);
	e.printStackTrace(System.out);
	}
	}
	}

/*
III. The main related code:

We have, generally three kind of requests:
-  execute Query();where we SELECT to return the ResultSet,
-  executeUpdate ();  where we CREATE TABLE, 
UPDATE, INSERT, DROP, or  DELETE, 
which return a confirmation digit,
-  execute(); 

The main related code is the following:

Statement stmt = conn.createStatement();
ResultSet rst = stmt.executeQuery("SELECT * (or other 
field) FROM TABLE"); or
ResultSet rst = stmt.executeUpdate ("CREATE TABLE, UPDATE, 
INSERT, DROP, or  DELETE requests");

We can therafter access to the related columns of the table by codes, 
such as:
int Value = rst.getInt(n);//get the int from the nth columun
String Data = rst.getString("Data");

And such as:
while(rst.next()){
int value = rst.getInt("culumnA");
String str = rst.getStrig ("columnB";
....
}
Finally:
ResultSet.close();
Statement.close();
Connection.close();


IV. Queries on a built Students database:
*/

	import java.sql.*;
	import oracle.jdbc.*;
	import oracle.jdbc.OracleDriver;	

	public class showTable{
	public static void main (String args []) throws SQLException
	{
	DriverManager.registerDriver (new oracle.jdbc.OracleDriver());
	Connection conn = DriverManager.getConnection("jdbc:oracle:
	thin:@HOST:1521:XE","User","Password");		
	Statement stmt = conn.createStatement();
	try {
	ResultSet rst = stmt.executeQuery( "SELECT * FROM Students 
	WHERE STUDENTID ='103' " );
	try {
	while ( rst.next() ) {
	int numColumns = rst.getMetaData().getColumnCount();
	for ( int i = 1 ; i <= numColumns ; i++ ) {//Column numbers start at 1.
	System.out.println( "COLUMN " + i + " = " + rst.getObject(i) );
	}
	System.out.println();
	}
	} finally {
	rst.close();
	}
	} finally {
	stmt.close();
	}
	}
	}// End of class showtable