Create dynamic drop down box - php

Question

I am trying to create a dependent dynamic drop down box on three input fields. At the moment the each input field is getting their data from their individual tables called tour_type, countries and destination. This is the form:
<label>Tour Type </label>
<select id="tourtype" name="tourtype" required>
<option value="" selected="selected">--Select--</option>
<?php
$sql=mysql_query("Select tour_type_id,tour_name from tour_type");
while($row=mysql_fetch_array($sql))
{
$tour_type_id=$row['tour_type_id'];
$name=$row['tour_name'];
echo "<option value='$tour_type_id'>$name</option>";
}
?>
</select>
<label>Country </label>
<select id="country" name="country" class="country" required>
<option value="" selected="selected">-- Select --</option>
<?php
$sql=mysql_query("SELECT * FROM `countries` where `tour_type_id` = ?"); //what should i put in here?
while($row=mysql_fetch_array($sql))
{
$cid=$row['countries_id'];
$name=$row['countries_name'];
echo "<option value='$cid'>".$name."</option>";
}
?>
</select>
<label>Destination </label>
<select id="destination" name="destination" class="destination" required>
<option value="" selected="selected">-- Select --</option>
<?php
$sql=mysql_query("SELECT * FROM `destination` where `countries_id` = ?");//what should i put in here?
while($row=mysql_fetch_array($sql))
{
$destination_id=$row['destination_id'];
$name=$row['destination_name'];
echo "<option value='$destination_id'>".$name."</option>";
}
?>
</select>
This is the javascript at the top of the form
<script type="text/javascript">
$(document).ready(function()
{
$(".country").change(function()
{
var id=$(this).val();
var dataString = 'id='+ id;
$.ajax
({
type: "POST",
url: "ajax.php",
data: dataString,
cache: false,
success: function(html)
{
$(".destination").html(html);
}
});
});
});
</script>
Finally these are the 3 tables i.e. tour_type, countries and destination respectively:
Can anyone help me on this?
How do I make each drop down box dependable on each other? For e.g. If i select Culture on the 1st drop down, then only Holland and Belgium should show in the 2nd drop down. So now if i select Holland from 2nd drop down, then Amsterdam should show in the 3rd drop down.
This is the ajax.php which i am not too sure if it is right.
<?php
include('../config.php');
if($_POST['']) //what should i put in here?
{
$id=$_POST['']; //what should i put in here?
$sql=mysql_query //this is where i do not know what to put;
while($row=mysql_fetch_array($sql))
{
//And what should i be placing here
}
}
?>
This is what the web front end form looks like after implementing the code provided by dianuj. I still can not select the 2nd and 3rd drop down boxes:

Answer 1

So first you have the tour type select box. So just move the code for fetching countries based on tour type to ajax.php. Also include one more parameter to distinguish which type(tour type,country etc) you are posting. so you will get the id and based on the type parameter you can fetch from different tables. Then create a selectbox HTML snippet and output it. This will return for the AJAX call and you can insert the HTML.
You can use ajax get here and can use the shorthand version like
$.get('ajax,php?id=idhere&type=country', function(data) {
$('#country_result').html(data);
});
Where result is the id of div to which the select box has to be inserted.
So the HTML part will be like
<div id="country_result"></div> //Country select box goes here
<div id="destination_result"></div> //Country select box goes here

Answer 2

The simplest approach is to fetch select options from the server when the selections change, like so:
$('#tour_type').change(function() {
// load country options
});
$('#country').change(function() {
// load destination options
});
The server should simply return a snippet of HTML containing the available options for country and destination.

Answer 3

here you go you have to fetch the options from the ajax.php do not place the query in second dropdown
<label>Tour Type </label>
<select id="tourtype" name="tourtype" required>
<option value="" >--Select--</option>
<?php
$sql=mysql_query("Select tour_type_id,tour_name from tour_type");
while($row=mysql_fetch_array($sql))
{
$tour_type_id=$row['tour_type_id'];
$name=$row['tour_name'];
echo "<option value='$tour_type_id'>$name</option>";
}
?>
</select>
<label>Country </label>
<select id="country" name="country" class="country" required>
<option value="">-- Select --</option>
</select>
<label>Destination </label>
<select id="destination" name="destination" class="destination" required>
<option value="">-- Select --</option>
</select>
initially country and destination drop down should be empty here your js goes
$('#tour_type').change(function() {
var id=$(this).val();
$.ajax
({
type: "POST",
url: "ajax.php",
data: "&id="+id+"&get_countries=1",
success: function(html)
{
$("#country").append(html);
}
});
});
$('#country').change(function() {
var id=$(this).val();
$.ajax
({
type: "POST",
url: "ajax.php",
data: "&id="+id+"&get_destination=1",
success: function(html)
{
$("#destination").append(html);
}
});
});
And your ajax.php
<?php
if($_REQUEST['get_countries']){
$sql=mysql_query("SELECT * FROM `countries` where `tour_type_id`=".$_REQUEST['id']);
$countries="";
while($row=mysql_fetch_array($sql))
{
$cid=$row['countries_id'];
$name=$row['countries_name'];
$countries.= "<option value='".$cid."'>".$name."</option>";
}
echo $countries;
}elseif($_REQUEST['get_destination']){
$destination="";
$sql=mysql_query("SELECT * FROM `destination` where `country_id` =".$_REQUEST['id'])
while($row=mysql_fetch_array($sql))
{
$destination_id=$row['destination_id'];
$name=$row['destination_name'];
$destination.= "<option value='".$destination_id."'>".$name."</option>";
}
echo $destination;
}
?>
Hope it works fine

Answer 4

<label>Tour Type </label>
<select id="tourtype" name="tourtype" required onchange="get_country($(this).val())">
<option value="" selected="selected">--Select--</option>
<?php
$sql=mysql_query("Select tour_type_id,tour_name from tour_type");
while($row=mysql_fetch_array($sql))
{
$tour_type_id=$row['tour_type_id'];
$name=$row['tour_name'];
echo "<option value='$tour_type_id'>$name</option>";
}
?>
</select>
<label>Country </label>
<select id="country" name="country" class="country" required onchange="get_destination($(this).val())">
<option value="" selected="selected">-- Select --</option>
</select>
<label>Destination </label>
<select id="destination" name="destination" class="destination" required>
<option value="" selected="selected">-- Select --</option>
</select>
<script>
function get_country(tour_type)
{
$.post("ajax.php",{get_country:tour_type},function(data){
var data_array = data.split(";");
var number_of_name = data_array.length-1;
var value;
var text;
var opt;
var temp_array;
for(var i=0; i<number_of_name; i++)
{
value=temp_array[i];
//alert(value);
text=temp_array[i];
opt = new Option(text,value);
$('#country').append(opt);
$(opt).text(text);
}
$("#country").prop("disabled", false);
});
}
//same way script for getting destination
</script>
// now in ajax file
if(isset($_POST["get_country"]))
{
$tour_type = str_replace("'","",stripslashes(htmlentities(strip_tags($_POST["get_country"]))));
$country_select = mysql_query("select * from country where tour_type_id = '$tour_type'");
$country="";
while($country_row = mysql_fetch_array($country_select))
{
$country = $country.$country_row["country"].";";
}
echo $country;
}
// same way ajax for destination