how to perform operation on data retrieved from database in jsp?

i developed a project on student marks system.in this project i successfully entered marks into the database from the jsp page and i can also retrieved data from database based on the input given but i want to do some addition operation on data retrieved from database and the present to the user PLEASE HELP ME TO SOLVE THIS PROBLEM THANKS IN ADVANCE

View Answers

June 17, 2011 at 3:52 PM

1)application.jsp:

<%@ page import="java.sql.*" %>
<html>
<head>
<script language="javascript">
function editRecord(id){
    var f=document.form;
    f.method="post";
    f.action='edit.jsp?id='+id;
    f.submit();
}
function deleteRecord(id){
    var f=document.form;
    f.method="post";
    f.action='delete.jsp?id='+id;
    f.submit();
}
</script>
</head>
<body>

<br><br>
<form method="post" name="form">
<table border="1">
<tr><th>First Name</th><th>Last Name</th><th>Address</th><th>Contact No</th><th>Marks</th></tr>
<%
Connection con = null;
String url = "jdbc:mysql://localhost:3306/";
String db = "test";
String driver = "com.mysql.jdbc.Driver";
String userName ="root";
String password="root";

int sumcount=0;
Statement st;
try{
Class.forName(driver).newInstance();
con = DriverManager.getConnection(url+db,userName,password);
String query = "select * from student";
st = con.createStatement();
ResultSet rs = st.executeQuery(query);
%>
<%
while(rs.next()){
%>
<tr><td><%=rs.getString("firstname")%></td>
<td><%=rs.getString("lastname")%></td>
<td><%=rs.getString("address")%></td>
<td><%=rs.getString("phone")%></td>
<td><%=rs.getString("marks")%></td>

<td><input type="button" name="edit" value="Edit" style="background-color:green;font-weight:bold;color:white;" onclick="editRecord(<%=rs.getString("id")%>);" ></td>
<td><input type="button" name="delete" value="Delete" style="background-color:red;font-weight:bold;color:white;" onclick="deleteRecord(<%=rs.getString("id")%>);" ></td>
</tr>
<%
}
%>
<%
}
catch(Exception e){
e.printStackTrace();
}
%>
</table>
</form>
</body>
</html>

2)edit.jsp:

<%@page language="java"%>
<%@page import="java.sql.*"%>
<form method="post" action="update.jsp">
<table border="1">
<tr><th>First Name</th><th>Last Name</th><th>Address</th><th>Contact No</th><th>Marks</th></tr>
<%
String id=request.getParameter("id");
int no=Integer.parseInt(id);
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root");
String query = "select * from student where id='"+no+"'";
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
while(rs.next()){
%>
<tr>
<td><input type="text" name="fname" value="<%=rs.getString("firstname")%>"></td>
<td><input type="text" name="lname" value="<%=rs.getString("lastname")%>"></td>
<td><input type="text" name="address" value="<%=rs.getInt("address")%>"></td>
<td><input type="text" name="phone" value="<%=rs.getString("phone")%>"></td>
<td><input type="text" name="marks" value="<%=rs.getString("marks")%>"></td>

<td><input type="hidden" name="id" value="<%=rs.getString(1)%>"></td>
</tr>
<tr>
<td><input type="submit" name="Submit" value="Update" style="background-color:#49743D;font-weight:bold;color:#ffffff;"></td>
</tr>
<%
}
}
catch(Exception e){}
%>
</table>
</form>

June 17, 2011 at 3:55 PM

3)update.jsp:

<%@page import="java.sql.*"%>
<%
        String ide=request.getParameter("id");
        int num=Integer.parseInt(ide);
        String fname=request.getParameter("fname");
        String lname=request.getParameter("lname");
        String address=request.getParameter("address");
        int contact=Integer.parseInt(request.getParameter("phone"));
        int marks=Integer.parseInt(request.getParameter("marks"));
            try{
                Connection conn = null;
                Class.forName("com.mysql.jdbc.Driver").newInstance();
                conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root", "root");
                Statement st=null;
                st=conn.createStatement();
                st.executeUpdate("update student set firstname='"+fname+"',lastname='"+lname+"',address='"+address+"',phone="+contact+",marks="+marks+" where id="+num+"");
                response.sendRedirect("application.jsp");
            }
            catch(Exception e){
                System.out.println(e);
            }
%>

4)delete.jsp:

<%@page import="java.sql.*"%>
<%
String id=request.getParameter("id");
int no=Integer.parseInt(id);
int sumcount=0;
    try {
        Class.forName("com.mysql.jdbc.Driver").newInstance();
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root");
        Statement st = conn.createStatement();
        st.executeUpdate("DELETE FROM student WHERE id = '"+no+"'");
        response.sendRedirect("application.jsp");
    }
    catch(Exception e){}
%>