METODA:
	// a java preparedstatement example
	 public static void updateContactTitleForCity (
	   Connection conn,
	   String contactTitle,
	   String city
	 )
	 throws SQLException
	 {
	   try
	   {
	     // create our java preparedstatement using a sql update query
	     PreparedStatement ps = conn.prepareStatement(
	       "UPDATE Customers SET ContactTitle = ? WHERE City = ?");

	     // set the preparedstatement parameters
	     ps.setString(1, contactTitle);
	     ps.setString(2, city);
	     // call executeUpdate to execute our sql update statement
	     ps.executeUpdate();
	     ps.close();
	   }
	   catch (SQLException se)
	   {
	     // log the exception
	     throw se;
	   }
	 }



MAIN:

      String connectionUrl = "jdbc:sqlserver://localhost:1433;" +
         "databaseName=NORTHWND;user=piotr;password=student";

      try {
          // Establish the connection.
          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
          con = DriverManager.getConnection(connectionUrl);

          stmt = con.createStatement();
          updateContactTitleForCity(con, "AAAA", "Berlin");
       }

       // Handle any errors that may have occurred.
       catch (Exception e) {
          e.printStackTrace();
       }
      finally {
          if (rs != null) try { rs.close(); } catch(Exception e) {}
          if (stmt != null) try { stmt.close(); } catch(Exception e) {}
          if (con != null) try { con.close(); } catch(Exception e) {}
       }