div class="row">
<div class="col-md-3">
<div class="form-group">
<?php $ilList = $db->query("SELECT * FROM il")->fetchAll(PDO::FETCH_ASSOC); ?>
<select id="il" class="selectpicker">
<option>Şehir Seçiniz</option>
<?php foreach ($ilList as $key => $value){echo '<option value="'.$$value['il_id'].'">'.$value['il_adi'].'</option>'; } ?>
</select>
</div>
</div>

<div class="col-md-3">
<div class="form-group">
<select id="ilce" class="selectpicker">
<?php $ilid = $_POST['il'];
$ilceList = $db->query("SELECT * FROM ilce where il='".$ilid."'")->fetchAll(PDO::FETCH_ASSOC);
foreach($ilceList as $key => $value) { echo '<option value"'.$value['ilce_id'].'">'.$value['ilce_adi'].'</option>'; } ?>
</select>
</div>
</div>

<script type="text/javascript">
$(document).ready(function(){
$("#il").change(function(){
var ilid = $(this).val();
$.ajax({
type:"POST",
data:{"il":ilid},
success:function(e)
{
$("#ilce").show();
$("#ilce").html(e);
}
});
})
});</script>

<div class="col-md-3">
<div class="form-group">
<button class="btn btn-custom btn-custom-secondary btn-wide ara">Ara</button>
</div>
</div>
                            </div>