Delete a row from database by id

I m creating a small application using servlet. There is a form (index.jsp)having 10 fields on submitting the form all the values are added in to database and page is redirected to a new page that contains entries of submittes form. Now there are 2 extra columns(10+2) for "DELETE" AND "UPDATE". On clicking delete which is hyper link that particular row should be deleted and on clicking update , we should be able to update its value. So anyone will tell me how to give hyper link to Delete and Update and delete query (by id).???

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November 9, 2012 at 2:58 PM

Here is an application that allow user to update and delete record from database.

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>Name</th><th>Address</th><th>Contact No</th><th>Email</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 employee";
st = con.createStatement();
ResultSet rs = st.executeQuery(query);
%>

<%
while(rs.next()){
%>
<tr><td><%=rs.getString(2)%></td>
<td><%=rs.getString(3)%></td>
<td><%=rs.getString(4)%></td>
<td><%=rs.getString(5)%></td>
<td><input type="button" name="edit" value="Edit" style="background-color:#49743D;font-weight:bold;color:#ffffff;" onclick="editRecord(<%=rs.getString(1)%>);" ></td>
<td><input type="button" name="delete" value="Delete" style="background-color:#ff0000;font-weight:bold;color:#ffffff;" onclick="deleteRecord(<%=rs.getString(1)%>);" ></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>Name</th><th>Address</th><th>Contact No</th><th>Email</th></tr>
<%
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");
String query = "select * from employee where id='"+no+"'";
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
while(rs.next()){
%>
<tr>
<td><input type="text" name="name" value="<%=rs.getString("name")%>"></td>
<td><input type="text" name="address" value="<%=rs.getString("address")%>"></td>
<td><input type="text" name="contact" value="<%=rs.getInt("contactNo")%>"></td>
<td><input type="text" name="email" value="<%=rs.getString("email")%>"></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>

November 9, 2012 at 3:02 PM

continue..

3)update.jsp:

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

<%
String ide=request.getParameter("id");
int num=Integer.parseInt(ide);
String name=request.getParameter("name");
String address=request.getParameter("address");
int contact=Integer.parseInt(request.getParameter("contact"));
String email=request.getParameter("email");
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 employee set name='"+name+"',address='"+address+"',contactNo="+contact+",email='"+email+"' where id='"+num+"'");
response.sendRedirect("/examples/jsp/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 employee WHERE id = '"+no+"'");
response.sendRedirect("application.jsp");
}
catch(Exception e){}
%>

For more information, visit the following link:

http://www.roseindia.net/answers/viewqa/JSP-Servlet/15955-Servlets.html

April 23, 2013 at 10:11 AM

but this ans is not working.it is not passing the data from table as js function argumnt..plss help me...

Delete a row from database by id

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