<form method="post" action="updatedemo.jsp">
 <table width="50%" border="1" align="center">
   <tr>
     <td width="41%" height="32"><em><strong>name</strong></em></td>
     <td width="59%">
        <input type="text" name="name" value="<%= resultset.getString(1) %>">
    </td>
  </tr>
  <tr>
     <td height="34"><em><strong>lastname</strong></em></td>
     <td>
        <input type="text" name="lastname" value="<%= resultset.getString(2) %>">
     </td>
     <input type="submit" name="submit">
    </form>
    <%
     }
     %>
    </BODY>
</HTML>

<%@page import="java.sql.*"%>

<%

String name=request.getParameter("name");
//int no=Integer.parseInt(code);
String lastname=request.getParameter("lastname");
try{
Connection conn = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/demo","root", "jack");
Statement st=null;
st=conn.createStatement();




String sqlEDIT="UPDATE INTO demoproject(name,lastname) VALUES(?,?)";
java.sql.PreparedStatement ps=conn.prepareStatement(sqlEDIT);
ps.setString(1,name);
ps.setString(2,lastname);

ps.executeUpdate();
   int i=ps.executeUpdate();
if(i>0)
        {
            out.print("project added into database");
            response.sendRedirect("demo1.jsp");
        }
}
catch(Exception e){
System.out.println(e);
    }
%>

UPDATE table_name
SET column1=value1,column2=value2,...
WHERE some_column=some_value;