Search city for selected category - php

Question

This ps_search.php page has dropdown for categories like laptop, bags etc... and a dropdown for city. if a user wants to post an ad means he/she wants to sell something on website , first of all a category is selected like laptop, bag or anything else. and then city is selected from where the ad is posted. if, for instance, a user posts an ad of laptop from city1 and we have no more ads of laptops from other cities . then after selecting laptop , city 1 should appear in a dropdown menu. i have two files ps_search.php ang get_city.php
//ps_search.php
<form name="search" method="post" action="<?php echo $base_url ?>search_rides.php?go">
<table width="100%" border="0" cellpadding="4" cellspacing="0" id="tbsrch-engine">
<tbody>
<tr>
<td height="61">
<strong>Choose Category:</strong>
</td>
<td>
<select name="category_id" id="category_id" style="width: 155px;" onChange="get_city(this.value,'<?php echo $base_url ?>dropdown/get_city.php')">
<option value="0">Any</option>
<?php $query = "SELECT category_id as id, category_name as name FROM tbl_ps_category ";
$result = mysql_query($query);
?>
<?php while ( $row = mysql_fetch_array($result)) {?>
<option value="<?php echo $row['id'].'-'.$row['name']; ?>"><?php echo $row['name']?></option>
<?php }?>
</select>
</td>
</tr>
<tr>
<td height="40">
<strong>City:</strong>
</td>
<td>
<div id="models">
<select name="city_id" id="city_id">
<option value="0">Any</option>
</select>
</div>
</td>
</tr>
<tr>
<td height="32"/>
<td>
<input type="submit" name="button2" id="button2" value="Search an Ad" class="fbutton"/>
</td>
</tr>
</tbody>
</table>
</form>
//get_city.php
<?php
include('../Connections/photohive.php');
$id = $_REQUEST['id'];
$explode = explode('-',$id);
$id = $explode[0];
$sql = "SELECT city_id FROM ".$ps_prefix."product WHERE category_id=".$id;
$query = mysql_query($sql);
//exit;
?>
<select name="city_id" id="city_id" style="width:155px;">
<option value="0">Any</option>
<?php
while ($row = mysql_fetch_array($query)){
$q1= sprintf("Select cityname from tbl_city where city_id='%s'" , mysql_real_escape_string($row['city_id']), " ORDER BY cityoreder ASC");
$r1= mysql_query($q1);
while($row2= mysql_fetch_assoc($r1))
{
?>
<option value="<?php echo $row['city_id']?>"><?php echo $row2['cityname']?></option>
<?php
}
}
?>
</select>
i have included js file as well
<script src="<?php echo $base_url;?>js/jquery.ajaxq-0.0.1.js" type="text/javascript"></script>
Please help me....

Answer 1

Your javascript should look like this:
(function ($) {
// When category select changes
$('#category_id').change(function() {
// make ajax query to get cities
$.get('get_city.php', {id: $(this).val())
.done(function(response) {
// get the cities dropdown from response and insert into page
$('#models').html(response);
});
});
})(jQuery);
I personally don't like returning HTML in my ajax calls. I usually prefer to return a JSON object and then parse out the HTML client side (usually using Handlebars). I think it's cleaner that way.