Hello all, I'm an amateur at PHP coding, and am currently enrolled in a PHP and MySQL class that uses the PHP Programming with MySQL textbook, by Don Gosselin. I'm trying to get this simple Shopping Cart script to work, because it's the step-by-step example script for Chapter 11, but I keep getting the following errors on ShowCart.php when I try to add an item to the cart.
Line 78:
$QueryResult = mysqli_query($this->DBConnect, $SQLstring)
Line 80 and 81:
. "<p>Error code " . mysqli_errno($this->DBConnect)
. ": " . mysqli_error($this->DBConnect)) . "</p>";
I've read "Couldn't fetch mysqli" errors are because the connection was closed prior to those lines, but I don't see any indication of a connection closure. I have no idea what to do, as all the code was given to me in the book, I merely copied it down.
Here's the ShoppingCart.php code:
<?php
class ShoppingCart {
private $DBConnect = "";
private $DBName = "";
private $TableName = "";
private $Orders = array();
private $OrderTables = array();
function construct() {
$this->DBConnect = mysqli_connect("localhost", "root", "passHere");
if (mysqli_connecT_errno())
die("<p>Unable to connect to the database server.</p>"
. "<p>Error code " . mysqli_connect_errno()
. ": " . mysqli_connect_error()) . "</p>";
}
public function setDatabase($Database) {
$this->DBName = $Database;
$this->DBConnect->select_db($this->DBName)
Or die("<p>Unable to select the databbase.</p>"
. "<p>Error code " . mysqli_errno($this->DBConnect)
. ": " . mysqli_error($this->DBConnect)) . "</p>";
}
public function setTable($Table) {echo $table."<br />";
$this->TableName = $Table;
}
public function getProductList() {
$SQLstring = "SELECT * FROM $this->TableName";
$QueryResult = $this->DBConnect->query($SQLstring)
Or die("<p>Error code " . mysqli_errno($this->DBConnect)
. ": " . mysqli_error($DBConnect)) . "</p>";
echo "<table width='100%' border='1'>";
echo "<tr><th>Product</th><th>Description</th><th>Price Each</th><th>Select Item</th></tr>";
$Row = $QueryResult->fetch_row();
do {
echo "<tr><td>{$Row[1]}</td>";
echo "<td>{$Row[2]}</td>";
printf("<td align='center'>$%.2f</td>", $Row[3]);
echo "<td align ='center'>
<a href='ShowCart.php?PHPSESSID=" . session_id()
. "&operation=addItem&productID=" . $Row[0]
. "'>Add</a></td></tr>";
$Row = $QueryResult->fetch_row();
} while ($Row);
echo "</table>";
}
public function addItem() {
$ProdID = $_GET['productID'];
if (array_key_exists($ProdID, $this->Orders))
exit("<p>You already selected that item! Click your
browser's back button to return to the
previous page.</p>");
$this->Orders[$ProdID] = 1;
$this->OrderTable[$ProdID] = $this->TableName;
}
function _wakeup() {
$this->DBConnect = new mysqli("localhost", "staticlo_shane", "shinfoosh");
if (mysqli_connect_errno())
die("<p>Unable to connect to the database server.</p>"
. "<p>Error code " . mysqli_connect_errno()
. ": " . mysqli_connect_error()) . "</p>";
$this->DBConnect->Select_db($this->DBName)
Or die("<p>Unable to select the database.</p>"
. "<p>Error code " . mysqli_errno($$this->DBConnect)
. ": " . mysqli_error($this->DBConnect)) . "</p>";
}
public function showCart() {
if (empty($this->Orders))
echo "<p>Your shopping cart is empty!</p>";
else {
echo "<table width='100%' border='1'>";
echo "<tr><th>Remove Item</th><th>Product</th><th>Quantity</th><th>
Price Each</th></tr>";
$Total = 0;
foreach($this->Orders as $Order) {
$SQLstring = "SELECT * FROM "
. $this->OrderTable[key($this->Orders)] . "
WHERE productID='" . key($this->Orders) . "'";
$QueryResult = mysqli_query($this->DBConnect, $SQLstring)
Or die("<p>Unable to perform the query.</p>"
. "<p>Error code " . mysqli_errno($this->DBConnect)
. ": " . mysqli_error($this->DBConnect)) . "</p>";
$Row = mysqli_fetch_row($QueryResult);
echo "<td align='center'>";
echo "<a href='ShowCart.php?PHPSESSID=" . session_id()
. "&operation=removeItem&productID=" . $Row[0]
. "'>Remove</a></td>";
echo "<td>{$Row[1]}</td>";
echo "<td align='center''>$Order ";
echo "<a href='ShowCart.php?PHPSESSID=" . session_id() . "&operation=addOne&productID=" . $Row[0] . "'>Add</a>";
echo "<a href='ShowCart.php?PHPSESSID=" . session_id() . "&operation=removeOne&productID=" . $Row[0] . "'>Remove</a>";
echo "</td>";
printf("<td align='center'>$%.2f</td></tr>", $Row[3]);
$Total += $Row[3] * $Order;
next($this->Orders);
echo "<td align='center' colspan='2'><strong>Your shopping
cart contains " . count($this->Orders)
. " product(s).</strong></td>";
printf("<td align='center'><strong>Total: $%.2f</stong>
</td>", $Total);
echo "</table>";
}
echo "<tr><td align='center'><a href='ShowCart.php?PHPSESSID="
. session_id() . "&operation=emptyCart'><strong>
Empty Cart</strong></a></td>";
}
}
public function removeItem() {
$ProdID = $_GET['productID'];
unset($this->Orders[$ProdID]);
unset($this->OrderTable[$ProdID]);
}
function emptyCart() {
$this->Orders = array();
$this->OrderTale = array();
}
function _destruct() {
$this->DBConnect->close();
}
public function addOne() {
$ProdID = $_GET['productID'];
$this->Orders[$ProdID] += 1;
}
public function removeOne() {
$ProdID = $_GET['productID'];
$this->Orders[$ProdID] -= 1;
if ($this->Orders[$ProdID] == 0)
$this->removeItem();
}
}
?>
Here is the ShowCart.php code:
<?php
session_start();
require_once("ShoppingCart.php");
if (!isset($_SESSION['curCart']))
header("location:GosselinGourmetGoods.php");
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<meta name="Robots" content="nofollow, noindex" />
<link rel="stylesheet" type="text/css" media="screen" href="php_styles.css" />
</head>
<body>
<h1>Gosselin Gourmet Goods</h1>
<h2>Shop by Category</h2>
<p><a href="GosselinGourmetCoffees.php">Gourmet Coffees</a><br />
<a href="GosselinGourmetOlives.php">Specialty Olives</a><br />
<a href="GosselinGourmetSpices.php">Gourmet Spices</a></p>
<?php
$Cart = unserialize($_SESSION['curCart']);
if (isset($_GET['operation'])) {
if ($_GET['operation'] == "addItem")
$Cart->addItem();
if ($_GET['operation'] == "removeItem")
$Cart->removeItem();
if ($_GET['operation'] == "emptyCart")
$Cart->emptyCart();
if ($_GET['operation'] == "addOne")
$Cart->addOne();
if ($_GET['operation'] == "removeOne")
$Cart->removeOne();
}
$Cart->showCart();
$_SESSION['curCart'] = serialize($Cart);
?>
</body>
</html>
Here is the product page for "Specialty Olives" which is identical to the Coffees and Spices pages, save for the Table name changed to their respective products:
<?php
session_start();
require_once("ShoppingCart.php");
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Gosselin Gourmet Goods</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<meta name="Robots" content="nofollow, noindex" />
<link rel="stylesheet" type="text/css" media="screen" href="php_styles.css" />
</head>
<body>
<h1>Gosselin Gourmet Goods</h1>
<h2>Shop by Category</h2>
<p><a href="GosselinGourmetCoffees.php">Gourmet Coffees</a><br />
<a href="GosselinGourmetOlives.php">Specialty Olives</a><br />
<a href="GosselinGourmetSpices.php">Gourmet Spices</a></p>
<h2>Speciality Olives</h2>
<?php
$Database = "gosselin_gourmet";
$Table = "olives";
$Cart=!empty($_SESSION['curCart'])?unserialize($_SESSION['curCart']):new ShoppingCart();
$Cart->construct();
$Cart->setDatabase($Database);
$Cart->setTable($Table);
$Cart->getProductList();
$_SESSION['curCart'] = serialize($Cart);
?>
<p><a href='<?php echo "ShowCart.php?PHPSESSID=" . session_id() ?>'>Show Shopping Cart</a></p>
</body>
</html>
