Multiple conditions queries with PDO - php

Question

I asked this question in http://codereview.stackexchange.com and they wanted me to post it here. I couldn't get this code to work at all. I switched from regular mysql to pdo which is more safer. Could someone tell me what I'm missing here. I've been struggling with it for couple of day, and I could find exact answer when I first searched this site.
$input = $_POST['input'];
$categories = $_POST['category'];
$state = $_POST['state'];
$zipcode = $_POST['zipcode'];
$qq = $db->prepare(" SELECT * FROM classified ")or die(print_r($qq->errorInfo(), true));
/*** execute the prepared statement ***/
$qq->execute();
/*** echo number of columns ***/
$rows = $qq->fetch(PDO::FETCH_NUM);
if ($rows>0){
$query = (" SELECT * FROM classified ");
$cond = array();
$params = array();
if (!empty($input)) {
$cond[] = "title = ?";
$params[] = $input;
}
if (!empty($categories)) {
$cond[] = "id_cat = ?";
$params[] = $categories;
}
if (!empty($state)) {
$cond[] = "id_state = ?";
$params[] = $state;
}
if (!empty($zipcode)) {
$cond[] = "zipcode = ?";
$params[] = $zipcode;
}
if (count($cond)) {
$query .= ' WHERE ' . implode(' AND ', $cond)or
die(print_r($query->errorInfo(),true));
}
$stmt = $db->prepare($query);
$stmt->execute($params);
$ro = $stmt->fetch(PDO::FETCH_NUM);
}
if ($ro > 0) {
foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row)
{
echo $row['title'];
echo $row['categories'];
echo $row['state'];
echo $row['zipcode'];
}
}

Answer 1

I think it's a good idea to post an answer here rather than posting a link. I'm sure it will be useful for some people.
$input = $_POST['input'];
$categories = $_POST['category'];
$state = $_POST['state'];
$zipcode = $_POST['zipcode'];
$qq = $db->prepare(" SELECT * FROM classified ")or die(print_r($qq->errorInfo(),
true));
/*** execute the prepared statement ***/
$qq->execute();
/*** echo number of columns ***/
$rows = $qq->fetch(PDO::FETCH_NUM);
if ($rows>0){
$query = " SELECT * FROM classified where confirm='0' ";
if(!empty( $_POST['input'])) {
$query .= "AND title LIKE '%".$input."%' ";
}
if (!empty($_POST['category']) )
{
$query .= "AND id_cat = ".$categories." ";
}
if (!empty($_POST['state']) )
{
$query .= "AND id_state = ".$state." ";
}
if(!empty($_POST['zipcode'])) {
$query .= "AND zipcode = ".$zipcode." ";
}
$query .= "ORDER BY date ";
}
$stmt = $db->prepare($query);
$stmt->execute($params);
$result = $stmt->fetchAll();
// $ro = $stmt->fetch(PDO::FETCH_NUM);
// it didn't work when I tried to count rows
if ($result > 0) {
foreach ($result as $row)
{
echo $row['title'];
echo $row['categories'];
echo $row['state'];
echo $row['zipcode'];
}
}else{
echo " No data available";
}