Populate triple drop down list from database using Ajax and PHP
Posted on January 24, 2008
Filed Under ajax, php
I’ve got many email from people asking for populating triple drop down list from the database without refreshing page using Ajax and PHP after posting the first article related to the ajax dropdown list using php .In this post, I’ve put three drop down of country , state and city and the drop down’s value changes without refreshing the page. Now let show you how to create it quickly.
First create the following tables of country city and states,
CREATE TABLE `country` ( `id` tinyint(4) NOT NULL auto_increment, `country` varchar(20) NOT NULL default '', PRIMARY KEY (`id`) ) TYPE=MyISAM ; CREATE TABLE `state` ( `id` tinyint(4) NOT NULL auto_increment, `countryid` tinyint(4) NOT NULL, `statename` varchar(40) NOT NULL, PRIMARY KEY (`id`) ) TYPE=MyISAM ; CREATE TABLE `city` ( `id` tinyint(4) NOT NULL auto_increment, `city` varchar(50) default NULL, `stateid` tinyint(4) default NULL, `countryid` tinyint(4) NOT NULL, PRIMARY KEY (`id`) ) TYPE=MyISAM ;
Now place the following form in the index.php file
<form method="post" name="form1"> <table border="0" cellpadding="0" cellspacing="0" width="60%"><tbody> <tr> <td width="150">Country</td> <td width="150"><select style="background-color: #ffffa0" name="country" onchange="getState(this.value)"><option>Select Country</option><option value="1">USA</option><option value="2">Canada</option> </select></td> </tr> <tr> <td>State</td> <td> <p id="statediv"> <select style="background-color: #ffffa0" name="state"><option>Select Country First</option> </select></td> </tr> <tr> <td>City</td> <td> <p id="citydiv"> <select style="background-color: #ffffa0" name="city"><option>Select State First</option> </select></td> </tr> </tbody></table> </form>
As you can see above, in the onChage event of the country drop down getState() function of the javascript is called which change the options values the State drop down, let’s look at the code the getState() function.
function getState(countryId)
{
var strURL="findState.php?country="+countryId;
var req = getXMLHTTP();
if (req)
{
req.onreadystatechange = function()
{
if (req.readyState == 4)
{
// only if "OK"
if (req.status == 200)
{
document.getElementById('statediv').innerHTML=req.responseText;
} else {
alert("There was a problem while using XMLHTTP:\n" + req.statusText);
}
}
}
req.open("GET", strURL, true);
req.send(null);
}
}
The code of the PHP file findState.php, which populate the options in the drop down of the state which is fetched from Ajax , is given below
<? $country=intval($_GET['country']);
$link = mysql_connect('localhost', 'root', ''); //changet the configuration in required
if (!$link) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('db_ajax');
$query="SELECT id,statename FROM state WHERE countryid='$country'";
$result=mysql_query($query);
?>
<select name="state" onchange="getCity(<?=$country?>,this.value)">
<option>Select State</option>
<? while($row=mysql_fetch_array($result)) { ?>
<option value=<?=$row['id']?>><?=$row['statename']?></option>
<? } ?>
</select>
In the above state dropdown, getCity() function is called in onChage event with countryId and stateId parameter, now let’s look at the code of the getCity() function
function getCity(countryId,stateId)
{
var strURL="findCity.php?country="+countryId+"&state="+stateId;
var req = getXMLHTTP();
if (req)
{
req.onreadystatechange = function()
{
if (req.readyState == 4) // only if "OK"
{
if (req.status == 200)
{
document.getElementById('citydiv').innerHTML=req.responseText;
} else {
alert("There was a problem while using XMLHTTP:\n" + req.statusText);
}
}
}
req.open("GET", strURL, true);
req.send(null);
}
}
In the above ajax function, findcity.php is called and this PHP file populate the city dropdown according to the supplied parameters country and state from get method. Now let’s look at the code of findcity.php,
<?php $countryId=intval($_GET['country']);
$stateId=intval($_GET['state']);
$link = mysql_connect('localhost', 'root', ''); //changet the configuration in required
if (!$link) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('db_ajax');
$query="SELECT id,city FROM city WHERE countryid='$countryId' AND stateid='$stateId'";
$result=mysql_query($query);
?>
<select name="city">
<option>Select City</option>
<?php while($row=mysql_fetch_array($result)) { ?>
<option value><?=$row['city']?></option>
<?php } ?>
</select>
And thats all, the triple drop down list of city, country and state using Ajax and PHP will be populated.
VIew Live Demo
To download full source code, click here
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Comments
64 Responses to “Populate triple drop down list from database using Ajax and PHP”
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[...] Populate triple drop down list (change options value) from … By Roshan I’ve got many email from people asking for populating triple drop down list from the database using Ajax and PHP after posting the first article related to the ajax dropdown list using php Now let show you how to create it quickly. Roshan Bhattarai’s Blog - PHP… - http://roshanbh.com.np [...]
I really love and enjoy your blog, Thanks.
Thanks a lott babak….
Nice job. Thanks!
After almost 2 months searching and learning AJAX from the bottom for my job problem, I found your site, I think this is my search end. Thanks Roshan, now I have learning new knowledge and have idea how to fix my previous AJAX code. Thank you so much for your code share.
Thanks Fajar…thanks a lottt…and please let me know some negative aspects of this blog as well..which will help me to improve the quality of this blog…
great blog with a TON of information.
looking for a suggestion on how to clear the 2nd and 3rd lists if the first is changed to prevent the possibility of submitting the wrong data.
thanks again
Sean
on that situation you can write conditions in fincity.php and findstate.php to clear the dropdown ..
hope this helps
makes sense, i was thinking that when the month changes the state drop down it would change the city drop down, and it doesn’t
i guess need to learn more about java script
Thanks u very much
I have done some modifications in database content and in php pages..
and i have run the same…its not working….
pls go thru my code…
function GetXmlHttpObject()
{
var xmlHttp=null;
try
{
xmlHttp=new XMLHttpRequest();
}
catch (e)
{
try{
xmlHttp=new ActiveXObject(”Msxml2.XMLHTTP”);
}
catch(e)
{
xmlHttp=new ActiveXObject(”Microsoft.XMLHTTP”);
}
}
return xmlHttp;
}
var xmlHttp;
function getstate(countryid)
{
xmlHttp=GetXmlHttpObject();
if(xmlHttp==null)
{
alert(”Browser Does not support HTTP request”)
return;
}
var url=”findstate.php?country=”+countryid;
xmlHttp.onreadystatechange=statechanged;
//alert(url);
xmlHttp.open(”GET”,url,true);
xmlHttp.send(null);
//alert(url);
}
function statechanged()
{ // alert(’url’);
if(xmlHttp.readyState==4 || xmlHttp.readyState==”complete”)
{
document.getElementById(’statediv’).innerHTML=xmlHttp.responseText;
}
else
alert(’wait’+xmlHttp.readyState);
}
function getcity(countryid,stateid)
{
xmlHttp=GetXmlHttpObject()
if(xmlHttp==null)
{
alert(”Browser Does not support HTTP request”)
return;
}
var url=”findcity.php?country=”+countryid+”&state=”+stateid;
xmlHttp.onreadystatechange=statechanged2;
xmlHttp.open(”GET”,url,true)
xmlHttp.send(null)
}
function statechanged2()
{
if(xmlHttp.readyState==4 || xmlHttp.readyState==”complete”)
{
document.getElementByID(’citydiv’).innerHTML=xmlHttp.responseText
}
}
Country
Select Country
India
USA
Canada
Stateselectstate
Cityselectcity
and my findstate.php code is like this
<?php
$countryid=$_GET["country"];
$con = mysql_connect(”localhost”,”root”,”root123″);
if(!$con)
{
die(”could not connect:”.mysql_error());
}
mysql_select_db(”testtool”,$con);
$query=”select id,statename from state where countryid=’”.$countryid.”‘;
$result=mysql_query($query) or die(mysql_error());
echo “<select name=’state’ onchange=’getcity(”.$countryid.”,this.value)”;
echo “”.count($result).”";
while($row=mysql_fetch_array($result))
{
“.$row['statename'].”
}
echo “;
mysql_close($con);
?>
After selecting country..it is displaying select option for state….
pls guide me….
well…after selecting country, it does display the dropdown for stat, I couldn’t get what is your problem !!
Thanks Roshan.
I love and enjoy your blog.
tell me some negative aspects of this blog as well,to improve myself.
Thanks u very much once again.
thx roshan!
just what i was looking for…
i have to link this with editable grid what will easy my life a lot!
thx again… :-))
btw…
i took a close look and noticed that i have no idea how can i make that after user makes his choice to, for example, open a page linked to what he choose?
nevertheless, this is still a good thing…
well mario….you can use window.open to open a new link using javascript
thx!
ill see what i can do…
im novice, so maybe a few line of code..(on your example)
City div is generated by php, and i really dont know where should i put it…
bye!
ok tell me in detail how do you want it to happen in detail so that I can tell you in detail…
ok thx!
i will use framesets so that combo boxes will remain visible…
in other words im planning to retain this kind of functionality as it seen on this site:
http://www.yxscripts.com/cs/examples/loader3.html
so basically when user chooses city (third combo option) script should automatically load some page in lower(down one) frame…
as list of the cities are automatically populated im wonder if that is even possible to do in this way…?
list is populated by admin directly to the database and then (data are) used on few pages of the same domain..
thx…
and yes, this is tested web site…
it has a lot of things to do still..
just to tell you that i found one php grid (php buider) that satisfied things that i needed..
thx anyway…
cheers!
nice to hear that mario..
yes, thank you!
nice thing though!
cheers!
on that situation you can write conditions in fincity.php and findstate.php to clear the dropdown ..
hope this helps
Thanks for sharing this.
Would you provide some code snipits or give some suggestions as to th functions I should use to write the conditions.
Hello Roshan. I am using same downloaded files (without change). After selecting country it shows empty city list in drop down. It does not get City Names. Why ?
Thank you very much for the tutorial. I am trying to create 4 drop down lists so i am modifying your code to include another list, but i am having problems.
This code populates the first two drop downs but when i try to populate the third drop down it is not make a call to the script. Im not sure why. In your code you have the onchange call in your php script so i thought that since this is a server side script the onchange needed to be in the html, but that doesnt seem to work. Do you have any ideas?
Thank you for all your help.
Hi, I’ve had problems loading the page. I can’t load the codes with just 2 dropdown boxes by Roshan as well. The database is connected. After selecting the country, the next dropdown box does not load. I’m stucked.
gosh why doesn’t roshan or anyone reply anymore?
Can you first check the the response in ajax by using alert(req.responseText); and you can see what is the response coming from that file
<select name=”state” onchange=”getCity(,this.value)”>
Hi i got this error message when i used firebug. Am clueless. It looks fine. Are you able to help?
does the demo codes have bugs? Because i am trying to debug the demo codes all these while.
I think there is one “,” extra in the onchange=”getCity(,this.value)” just remove , before this.value
It won’t let me post my comment.
@Sonny - LOL .. then how were u able to post that comment??
Sorry, that was my second comment. Turns out my first comment was too long.
I ended up figuring it out. I had put a piece of code for you to look at with me. But like I said… I figured it out.
I will say that I just found your blog yesterday and spent about 3 hours on your site reading over all the different PHP/AJAX topics.
I love it.
It is one of the best learning resources I’ve seen for people who are new to AJAX but need to implement it now.
Thanks, keep up the good work.
Sonny.
@sonny - Thanks a lot for the appreciation. If you liked this blog so much then why don’t you subscribe for the RSS feed of this blog by email..
http://www.feedburner.com/fb/a/emailverifySubmit?feedId=1456759&loc=en_US
and help me to become the blogging idol..
Love the auto-populate scripts. One question, how can you post a url based upon the final result “City”.
For example, once you get to the final combobox and choose “Los Angeles” is there a way to redirect to a specific url, based upon final selection. Sorry if this sounds confusing.
Thanks in advance
you can use the javascript code document.location=’abc.php’; on the onchange event of that particular dropdown…
I am listing County once the state is picked and it works like a charm but when I click on City- I get this message. There was a problem while using XMLHTTP:Not Found.
Web site is a work in progress. Please help.
Thanks
It is saying not found means…it not finding the the PHP file..can you check the location of the file and how you’re accessing it via javaScript
Found the mistake. Upper case and lower case issue - I was calling findCity.php but script was named findcity.php
Thank you for leading me in the right direction.
There is a problem with either the GetCity function or the findState.php. The problem is from this line
<select name=”state” onchange=”getCity(, this.value)”>
this.value is not being passed. The $country variable is. This is why so many people are having difficulty displaying the city. I am not sure why it is not being passing. The sample website works, so can you ensure that the findState.php on there is the same as you have listed?
Thank you in advance for your help.
@john - I think everything is right there with the code and only few people are having difficulty in using them due to some problem
Anyway, I’ll check the code again and see if something is wrong there or not
I had no problem testing the script (IE, Opera, FW) in a Windows XP PC with Apache, PHP, and Mysql installed manually. However, in another Windows PC where mysql is installed as a service, Apache and PHP installed manually, the second dropdown (State) will disappear after selecting an option from the country dropdown. It is only an observation. I hope some readers will find it useful.
Nice code, but it doesn’t seem to work for me. Nothing happens for me when I click on a value in the first list. I know all my stuff is set up correctly because using a different ajax script it works fine. I’m more then sure all of my variations of your code are correct, and I know the findstate.php works because if I type in findstate.php?country=2 or w/e It works fine. However there seems to be something wrong with it doing an auto refresh when you change the value.
Hmm, I seemed to have gotten it, your code in your zip file contains many illegal characters, using different ” errors out, and also your xml object is named differently, if you fixed that your code would be splendid
@Vec - Ya I see this I’ll surely going to make the correction..
Hi,
Everything works fine in FIrefox nut in IE I am experiencing error ‘Object Not found”
@Ramsey and @Vec - I’ve updated the code and mistake. You can download the source code now and it will work in IE properly as well you’ll not find “Object not found error”
i have problem in Ajax code. The error is encounter as
“There was a problem while using XMLHTTP:not found ”
plz tell me how to resolve it.
property look at the path of the file …as it is giving 404 not found error. You can check the path as well as character case of PHP file
Roshan,
I tried new version and it works very well. What can I say rather that you’re a star. Thanks a lot.
triple drop down list from database using Ajax and PHP
this code is not running?
Hi, Thank yooooooooooooooooooooou for this code, this work greatly. best wishes
Thank you for the script. am a beginner so your script was very helpful. But I am having trouble passing the variables upon submit. Please help.
What kind of problem you’re facing can you please explain it ?
oic, let’s try one more time. so sorry for the ultra long post
text field:
bracket input type=text name=’score[score]‘ value=” bracket
submit button:
bracketinput type=’hidden’ name=’action’ value=’submitscores’ bracket
bracket input type=’submit’ class=’button’ name=’submit’ value=’Submit >>’ bracket
To the brainee himself,
Thanks a lot Roshan,was looking exactly for the same thing,you made my life easier.
Bye
Regards,
dolly
Hi Roshan
Love your work.
However, when I change the option value of USA to be “USA” and echo $country in findState.php I receive the value 0. It doesn’t seem to like text?
Got it
@Damo - what was the problem and how did you solve it can you share it with us ?
The solution was simple. The first line in the php file has an intval function. This just needed to be removed.
However, I have been playing with your code and think I have found an issue. When the db contains a value with a space, only the data before the space is returned.
@Damo - intval() is there for preventing sql inject attack, do filter user input before using it with database.
Hi Roshan,
I just wanted to say thanks for sharing this script with us. I used it on my website to let the user select a category and then a genre thats in that category
There is only 1 thing i can’t seem to “adjust”, because when i do so the page where the genres will be loaded, does not load.
When i change:
req.onreadystatechange = function() {
if (req.readyState == 4) {
indto:
req.onreadygenrechange = function() {
if (req.readyGenre == 4) {
it doesnt work anymore. I also dont understand what that part axactly does, buy i am a real javascript n00bie
Greetz, Lessy