MySQL:Query with multiple conditions - php

Question

Im creating detailed product search.I verified that ,my variables are posted correctly, but the query don't finding anything. My question is:
What could be wrong in this query and what could be the best solution for detailed search in SQL?
<?php
if (
isset($_POST["productName"]) || isset($_POST["searchCategory"]) ||
isset($_POST["searchManufacturer"]) || isset($_POST["costFrom"]) ||
isset($_POST["costTo"])
){
$stmt=$user_home->runQuery("SELECT* FROM Products
WHERE (productTitle='$_POST[productName]' OR '$_POST[productName]' IS NULL)
AND (category='$_POST[searchCategory]' OR '$_POST[searchCategory]' IS NULL)
AND (manufacturer='$_POST[searchManufacturer]' OR '$_POST[searchManufacturer]' IS NULL)
");
echo $stmt->rowCount();
}

Answer 1

Try to proper forming WHERE statement. You should add conditions for productTitle, category, manufacturer fields only then isset proper POST fields.
Try this code:
<?php
if (
isset($_POST["productName"]) || isset($_POST["searchCategory"]) ||
isset($_POST["searchManufacturer"]) || isset($_POST["costFrom"]) ||
isset($_POST["costTo"])
){
$conditions = array();
if (isset($_POST['productName'])) {
$conditions[] = "(productTitle='".$_POST['productName']."')";
}
if (isset($_POST['category'])) {
$conditions[] = "(category='".$_POST['searchCategory']."')";
}
if (isset($_POST['searchManufacturer'])) {
$conditions[] = "(manufacturer='".$_POST['searchManufacturer']."')";
}
$where = implode(' AND ', $conditions);
if ($where) {
$where = 'WHERE '.$where;
} else {
$where = "";
}
$stmt=$user_home->runQuery("SELECT * FROM Products ". $where);
echo $stmt->rowCount();
}