Basic Steps in Using JDBC

First of all we have to know what is JDBC

What is JDBC?

JDBC is a piece of software that knows how to talk to the actual database server. JDBC is a registered trade mark.

Steps for JDBC

There are seven standard steps in querying databases:

1. Load the JDBC driver.
2. Define the connection URL.
3. Establish the connection.
4. Create a statement object.
5. Execute a query or update.
6. Process the results.
7. Close the connection.

Sample program

import java.sql.* ;

class JDBCQuery
{
public static void main( String args[] )
{
try
{
// Load the database driver
Class.forName( “sun.jdbc.odbc.JdbcOdbcDriver” ) ;

// Get a connection to the database
Connection conn = DriverManager.getConnection( “jdbc:odbc:Database” ) ;

// DriverManager.getConnection(“jdbc:mysql://localhost/test?user=root&password=mypass”);

// Print all warnings
for( SQLWarning warn = conn.getWarnings(); warn != null; warn = warn.getNextWarning() )
{
System.out.println( “SQL Warning:” ) ;
System.out.println( “State  : ” + warn.getSQLState()  ) ;
System.out.println( “Message: ” + warn.getMessage()   ) ;
System.out.println( “Error  : ” + warn.getErrorCode() ) ;
}

// Get a statement from the connection
Statement stmt = conn.createStatement() ;

// Execute the query
ResultSet rs = stmt.executeQuery( “SELECT * FROM Cust” ) ;

// Loop through the result set
while( rs.next() )
System.out.println( rs.getString(1) ) ;

// Close the result set, statement and the connection
rs.close() ;
stmt.close() ;
conn.close() ;
}
catch( SQLException se )
{
System.out.println( “SQL Exception:” ) ;

// Loop through the SQL Exceptions
while( se != null )
{
System.out.println( “State  : ” + se.getSQLState()  ) ;
System.out.println( “Message: ” + se.getMessage()   ) ;
System.out.println( “Error  : ” + se.getErrorCode() ) ;

se = se.getNextException() ;
}
}
catch( Exception e )
{
System.out.println( e ) ;
}
}
}