I am trying to populate a second dropdown list using the value selected from a first dropdown list using PHP and MySQL, and without refreshing the page. I thought this would be simple but can't get it to work so any help would be much appreciated.
So far, I have the following:
HTML Form (form.php)
<select name="list1" id="list1">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<select name="list2" id="list2">
</select>
JavaScript (within form.php)
<script type="text/javascript">
$("#list1").change(function() {
$("#list2").load("get_list2.php?id=" + $("#list1").val());
});
</script>
get_list2.php
require_once("config.php");
$q1 = mysql_query("SELECT * FROM mytable WHERE id = '$_GET[id]'");
while($row1 = mysql_fetch_assoc($q1)){
echo "<option>".$row1['item']."</option>";
}
Thanks!
Like other members have says, you should use PDO (with prepared statements) instead of mysql_.
One possible implementation:
HTML (form.php)
<select name="list1" id="list1">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<select name="list2" id="list2"></select>
<script type="text/javascript">
$("#list1").change(function() {
$.ajax({
url : "get_list2.php?id=" + $(this).val(),
type: 'GET',
dataType:'json',
success : function(data) {
if (data.success) {
$('#list2').html(data.options);
}
else {
// Handle error
}
}
});
});
</script>
PHP (get_list2.php)
require_once("config.php");
$id = $_GET['id'];
if (!isset($id) || !is_numeric($id))
$reponse = array('success' => FALSE);
else {
// Where $db is a instance of PDO
$query = $db->prepare("SELECT * FROM mytable WHERE id = :id");
$query->execute(array(':id' => $id));
$rows = $query->fetchAll(PDO::FETCH_ASSOC);
$options = "";
foreach ($rows as $row) {
$options .= '<option value="'. $row .'">'. $row .'</option>';
}
$response = array(
'success' => TRUE,
'options' => $options
);
}
header('Content-Type: application/json');
echo json_encode($response);
PS : not tested but it should works... I guess.
来源：https://stackoverflow.com/questions/15187487/using-php-mysql-to-populate-dropdown