PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

638 Chapter 28 Building a Shopping Cart
Listing 28.15
Continued
}
return false;
// insert each book
foreach($_SESSION['cart'] as $isbn => $quantity) {
$detail = get_book_details($isbn);
$query = "delete from order_items where
orderid = '".$orderid."' and isbn = '".$isbn."'";
$result = $conn->query($query);
$query = "insert into order_items values
('".$orderid."', '".$isbn."', ".$detail['price'].", $quantity)";
$result = $conn->query($query);
if(!$result) {
return false;
}
}
// end transaction
$conn->commit();
$conn->autocommit(TRUE);
}
return $orderid;
?>
The insert_order() function is rather long because you need to insert the customer’s
details, order details, and details of each book she wants to buy.
You will note that the different parts of the insert are enclosed in a transaction, beginning
with
$conn->autocommit(FALSE);
and ending with
$conn->commit();
$conn->autocommit(TRUE);
This is the only place in this application where you need to use a transaction. How do
you avoid having to do it elsewhere? Look at the code in the db_connect() function:
function db_connect() {
$result = new mysqli('localhost', 'book_sc', 'password', 'book_sc');
if (!$result) {
return false;
}
$result->autocommit(TRUE);
return $result;
}