Sum of Foreach Loop - php

Question

I'm trying to total a bill balance with a program I'm working on in PHP.
The code I use to pull the pricing is as such.
public function PackagePricing($arg) {
$query = <<<SQL
SELECT packageID
FROM customer_packages
WHERE active = :true
AND customerID = :arg
SQL;
$resource = $this->db->db->prepare( $query );
$resource->execute( array (
":true" => 1,
":arg" => 1,
));
foreach($resource as $row) {
self::GetPricing($row['packageID']);
}
}
public function GetPricing($arg) {
$query = <<<SQL
SELECT price
FROM products
WHERE id = :arg
SQL;
$resource = $this->db->db->prepare( $query );
$resource->execute( array (
":arg" => $arg,
));
$totalBill = 0;
foreach($resource as $row) {
$totalBill+= $row['price'];
}
echo $totalBill;
}
Now by my understanding this should work, but what I'm getting in turn is:
On the right you can see the billing total and rather than totaling out it's giving me each individually.

Answer 1

The error seems quite obvious. Here's your sequence in different words :
Get all packages ID.
Foreach package ID, get the price of the item (only one result is returned)
For that single result, add up all the prices (you only get one). Print it and go back to 2.
What you see is not 2 prices that have been added as strings in some sort of way. You simply prints subsequently 2 different prices. 10 & 30
GetPricing should return a price, and the foreach loop that calls it should make the sum.
$total = 0;
foreach($resource as $row)
{
$total += self::GetPricing($row['packageID']);
}
Hope this helps.