sandy
2 Answer(s) 2 years and 7 months ago
Posted in : JSP-Interview Questions
how to get drop down populated dynamically
October 21, 2010 at 4:26 PM
Hi Friend,
Create table country(country_id,country) in database and try the following code:
<%@page import="java.sql.*"%>
<html>
<form name="form" method="post" >
<b>Select a country:</b> </td>
<select name="sel"><option value=""><---Select---></option>
<%
Class.forName("com.mysql.jdbc.Driver").newInstance();
String connectionURL = "jdbc:mysql://localhost:3306/test";
Connection connection= DriverManager.getConnection(connectionURL, "root", "root");
PreparedStatement psmnt = connection.prepareStatement("select * from country ");
ResultSet results = psmnt.executeQuery();
while(results.next()){
String name = results.getString(2);
String id = results.getString(1);
%><option value="<%= name %>"><%=name%></option>
<%} results.close(); psmnt.close(); %>
</select><br>
</form>
Thanks
October 21, 2010 at 4:49 PM
Hi Friend,
If you want the code in ajax then try the following code:
1)country.jsp:
<%@page import="java.sql.*"%>
<html>
<head>
<script language="javascript" type="text/javascript">
var xmlHttp
var xmlHttp
function showState(str){
if (typeof XMLHttpRequest != "undefined"){
xmlHttp= new XMLHttpRequest();
}
else if (window.ActiveXObject){
xmlHttp= new ActiveXObject("Microsoft.XMLHTTP");
}
if (xmlHttp==null){
alert ("Browser does not support XMLHTTP Request")
return
}
var url= "city.jsp";
url += "?count=" +str;
xmlHttp.onreadystatechange = stateChange;
xmlHttp.open("GET", url, true);
xmlHttp.send(null);
}
function stateChange(){
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete"){
document.getElementById("state").innerHTML=xmlHttp.responseText
}
}
</script>
</head>
<body>
<select name='country' onchange="showState(this.value)">
<option value="none">Select</option>
<%
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("Select * from country");
while(rs.next()){
%>
<option value="<%=rs.getString(1)%>"><%=rs.getString(2)%></option>
<%
}
%>
</select>
<br>
<div id='state'>
<select name='state' >
<option value='-1'></option>
</select>
</div>
</body>
</html>
2)city.jsp:
<%@page language="java" import ="java.sql.*" %>
<%
String country=request.getParameter("count");
String buffer="<select name='state'><option value='-1'>Select</option>";
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("Select * from city where countryid='"+country+"' ");
while(rs.next()){
buffer=buffer+"<option value='"+rs.getString(2)+"'>"+rs.getString(3)+"</option>";
}
buffer=buffer+"</select>";
response.getWriter().println(buffer);
%>
We have used following database tables:
1)country
CREATE TABLE country (
countryid bigint(30) NOT NULL auto_increment,
countryname varchar(40) default NULL,
PRIMARY KEY (countryid)
)
2)city
CREATE TABLE city (
id bigint(40) NOT NULL auto_increment,
countryid int(100) default NULL,
city varchar(40) default NULL,
PRIMARY KEY (id)
)
The above code populate the second dropdown on selecting the value from the first dropdown.
Thanks
If you are facing any programming issue, such as compilation errors or not able to find the code you are looking for.
Ask your questions, our development team will try to give answers to your questions.
