e-commerce problem

[elle_girl]

I occur this problem at add_cart.php script
<?php
// This page adds prints to the shopping cart.
session_start();

if (is_numeric ($_GET['pid'])) {
// Check for a print ID.

// Set the page title and include the HTML header.
$page_title = 'Add to Cart';
include_once ('includes/header_customer_two.html');

// Check if the cart already contains one of these prints.
if (isset ($_SESSION['cart'][$pid])) {
	$qty = $_SESSION['cart'][$pid] + 1;
} else {
	$qty = 1;
}

// Add to the cart session variable.
$_SESSION['cart'][$pid] = $qty;

// Display a message.
echo '<p>The print has been added to your shopping cart.</p>';

} else { // Redirect
header ("Location: [url]http://[/url]" . $SERVER['HTTP_HOST'] . dirname($SERVER['PHP_SELF']) . "/index.php");
exit();

}

?>
<PRE><?php
print_r($_SESSION);
?></PRE>

It appear this problem
Notice: Undefined variable: pid in C:\Program Files\Apache Group\Apache2\htdocs\add_cart.php on line 13

Notice: Undefined variable: pid in C:\Program Files\Apache Group\Apache2\htdocs\add_cart.php on line 20

Can u help me to solve this coding problem?

[elle_girl]

browse_prints.php

<?php

// This page displays the available prints (products).

// Set the page title and include the HTML header.
$page_title = 'Browse the Prints';

require_once ('./mysql_connect.php'); // Connect to the database.

//Are we looking at a particular artist?
if (isset($GET['aid'])) {
$query = "SELECT FROM category, product WHERE category.category_id = product.category_id AND product.category_id = {$GET['aid']} ORDER BY product.product_name";
} else {
$query = "SELECT FROM category, product WHERE category.category_id = product.category_id ORDER BY category.last_category ASC, product.product_name ASC";
}

echo '<table border="0" width="90%" cellspacing="3" cellpadding="3" align="center">
<tr>
<td align="left" width="20%"><b>Author</b></td>
<td align="left" width="20%"><b>Book Title</b></td>
<td align="left" width="40%"><b>Description</b></td>
<td align="right" width="20%"><b>Price</b></td>
</tr>';

// Display all the URLs.
$result = mysql_query ($query);
while ($row = mysql_fetch_array ($result, MYSQL_ASSOC)) {

// Display each record.
echo " <tr>
	<td align=\"left\"><a href=\"browse_prints.php?aid={$row['category_id']}\"> {$row['last_category']}, {$row['first_category']} {$row['middle_category']}</a></td>
	<td align=\"left\"><a href=\"view_print.php?pid={$row['product_id']}\">{$row['product_name']}</td>
	<td align=\"left\">" . stripslashes($row['description']) . "</td>
	<td align=\"right\">\${$row['price']}</td>
</tr>\n";

} // End of while loop.

echo '</table>'; // Close the table.

mysql_close(); // Close the database connection.

?>

view_cart.php

<?php
// This page displays the contents of the shopping cart.
session_start();
// Set the page title and include the HTML header.
$page_title = 'View Your Shopping Cart';
include_once ('includes/header_customer_two.html');

// Check if the form has been submitted (to update the cart)
if (isset ($_POST['submit'])) {

foreach ($_POST['qty'] as $key => $value) {
	if (($value == 0) AND (is_numeric ($value))) {
		unset ($_SESSION['cart'][$key]);
	} elseif ( is_numeric ($value) AND ($value > 0) ) {
		$_SESSION['cart'][$key] = $value;
	}
}

}

// Check if the shopping cart is empty.
$empty = TRUE;
if (isset ($SESSION['cart'])) {
foreach ($SESSION['cart'] as $key => $value) {
if (isset($value)) {
$empty = FALSE;
}
}
}

// Display the cart if it's not empty.
if (!$empty) {

require_once ('./mysql_connect.php'); // Connect to the database.

// Retrieve all of the information for the prints in the cart.
$query = 'SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id IN (';
foreach ($_SESSION['cart'] as $key => $value) {
	$query .= $key . ',';
}
$query = substr ($query, 0, -1) . ') ORDER BY category.last_category ASC';
$result = mysql_query ($query);

// Create a table and a form.
echo '<table border="0" width="90%" cellspacing="3" cellpadding="3" align="center">
<tr>
	<td align="left" width="30%"><b>Author</b></td>
	<td align="left" width="30%"><b>Book Title</b></td>
	<td align="right" width="10%"><b>Price</b></td>
	<td align="center" width="10%"><b>Qty</b></td>
	<td align="right" width="10%"><b>Total Price</b></td>
</tr>

<form action="view_cart.php" method="post">
';

// Print each item.
$total = 0; // Total cost of the order.
while ($row = mysql_fetch_array ($result, MYSQL_ASSOC)) {

	// Calculate the total and subtotals.
	$subtotal = $_SESSION['cart'][$row['product_id']] * $row['price'];
	$total += $subtotal;

	// Print the row.
	echo " <tr>
	<td align=\"left\">{$row['first_category']} {$row['middle_category']} {$row['last_category']}</td>
	<td align=\"left\">{$row['product_name']}</td>
	<td align=\"right\">\${$row['price']}</td>
	<td align=\"center\"><input type=\"text\" size=\"3\" name=\"qty[{$row['product_id']}]\" value=\"{$_SESSION['cart'][$row['product_id']]}\" /></td>
	<td align=\"right\">$" . number_format ($subtotal, 2). "</td>
</tr>\n";
} // End of the WHILE loop.

// Print the footer and close the table and the form.
echo ' <tr>
	<td colspan="4" align="right"><b>Total : <b></td>
	<td align="right">$' . number_format ($total, 2) . '</td>
</tr>
</table><div align="center"><input type="submit" name="submit" value="Update My Cart" /></form><br /><br /><a href="checkout.php"><font size="+3">Continue To Purchase</font></a></div>';

mysql_close(); // Close the database connection.

} else {
echo '<p>Your cart is currently empty.</p>';
}

?>
<PRE><?php
print_r($_SESSION);
?></PRE>

view_print.php

<?php
// This page displays the details for a particular print.

if (is_numeric ($_GET['pid'])) {
// Make sure there's a print ID.

require_once ('./mysql_connect.php'); // Connect to the database.
$query = "SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id = {$_GET['pid']}";
$result = mysql_query ($query);
$row = mysql_fetch_array ($result, MYSQL_ASSOC);
mysql_close(); // Close the database connection.

// Set the page title and include the HTML header.
$page_title = $row['product_name'];
include_once ('includes/header_customer.html');

// Display a header.
echo "<div align=\"center\">

<b>{$row['product_name']}</b> by
{$row['first_category']} {$row['middle_category']} {$row['last_category']}
<br />{$row['description']}
<br />\${$row['price']}
<a href=\"add_cart.php?pid={$row['product_id']}\">Add to Cart</a>
</div><br />";

} else { // Redirect
header ("Location: [url]http://[/url]" . $SERVER['HTTP_HOST'] . dirname($SERVER['PHP_SELF']) . "/index.php");
exit();
}

?>

This is the script that deals with add_cart.php script.
Anyone out there can help me with my problem?

[bodzan]

...if I had to guess where is the problem my money would be on this statement:

$_SESSION['cart'][$pid]

because I think it should be:

$_SESSION['cart']['pid']

Start from there...

And PLEASE in the future to make your code readable just place it between [ php ] [ /php ] tags (without the spaces) because it will highlight it...

[elle_girl]

It appear this problem at view_cart.php script

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in C:\Program Files\Apache Group\Apache2\htdocs\view_cart.php on line 57

Please help me to solve this problem?
P.S. What u mean by This

COLOR=seagreen]And PLEASE in the future to make your code readable just place it between [ php ] [ /php ] tags (without the spaces) because it will highlight it...[/COLOR]

[Roger_Ramjet]

The error message means that your query failed. Add a line to echo $query BEFORE it is run, then we can see what is wrong with the SQL syntax. But check for typos in your table names etc as well.

[bodzan]

...as you can see when I posted code lines they are highlighted so are more readable...

Learn how to do it here

Show us which line is 57 of view_cart.php file and where is your sql statement which result is used in line 57...

[elle_girl]

This is the script for line 57

while ($row = mysql_fetch_array ($result, MYSQL_ASSOC)) {

[Weedpacket]

Originally posted by bodzan
...and where is your sql statement which result is used in line 57...

[elle_girl]

// Retrieve all of the information for the prints in the cart.
$query = 'SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id IN (';
foreach ($_SESSION['cart'] as $key => $value) {
$query .= $key . ',';
}
$query = substr ($query, 0, -1) . ') ORDER BY category.last_category ASC';
$result = mysql_query ($query);

[bodzan]

It might get you an idea what's wrong with it as Roger suggested...

[elle_girl]

It cannot appear the one that store before as got problem with the error in sql.
Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in C:\Program Files\Apache Group\Apache2\htdocs\view_cart.php on line 57

The array that print looks like these
Array
(
[cart] => Array
(
[pid] => 1
)

)

[bodzan]

... therefore there won't be any result to give you an error...

Or better, yet: to comment the line 57 that gives you an error...

[Roger_Ramjet]

If you are going to ask for help then you might at least listen to our requests and act on them

USE THE PHP TAGS TO HIGHLIGHT YOUR CODE

<?php
// This page displays the contents of the shopping cart.
session_start();
// Set the page title and include the HTML header.
$page_title = 'View Your Shopping Cart';
include_once ('includes/header_customer_two.html');

// Check if the form has been submitted (to update the cart)
if (isset ($_POST['submit'])) {

foreach ($_POST['qty'] as $key => $value) {
if (($value == 0) AND (is_numeric ($value))) {
unset ($_SESSION['cart'][$key]);
} elseif ( is_numeric ($value) AND ($value > 0) ) {
$_SESSION['cart'][$key] = $value;
}
}
}

// Check if the shopping cart is empty.
$empty = TRUE;
if (isset ($_SESSION['cart'])) {
foreach ($_SESSION['cart'] as $key => $value) {
if (isset($value)) {
$empty = FALSE;
}
}
}

// Display the cart if it's not empty.
if (!$empty) {

require_once ('./mysql_connect.php'); // Connect to the database.

// Retrieve all of the information for the prints in the cart.
$query = 'SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id IN (';
foreach ($_SESSION['cart'] as $key => $value) {
$query .= $key . ',';
}
$query = substr ($query, 0, -1) . ') ORDER BY category.last_category ASC';

//  Your error says that $result is not a valid resultset: THAT MEANS THE QUERY FAILED
// ---------------- ECHO THE QUERY AS REQUESTED BY US ---------

echo $query;

// ---------------- THEN POST IT SO WE CAN SEE WHAT IT SAYS

$result = mysql_query ($query);     

// Create a table and a form.
echo '<table border="0" width="90%" cellspacing="3" cellpadding="3" align="center">
<tr>
<td align="left" width="30%"><b>Author</b></td>
<td align="left" width="30%"><b>Book Title</b></td>
<td align="right" width="10%"><b>Price</b></td>
<td align="center" width="10%"><b>Qty</b></td>
<td align="right" width="10%"><b>Total Price</b></td>
</tr>
<form action="view_cart.php" method="post">
';

// Print each item.
$total = 0; // Total cost of the order.
while ($row = mysql_fetch_array ($result, MYSQL_ASSOC)) {  // LINE 57

// Calculate the total and subtotals.
$subtotal = $_SESSION['cart'][$row['product_id']] * $row['price'];
$total += $subtotal;

// Print the row.
echo " <tr>
<td align=\"left\">{$row['first_category']} {$row['middle_category']} {$row['last_category']}</td>
<td align=\"left\">{$row['product_name']}</td>
<td align=\"right\">\${$row['price']}</td>
<td align=\"center\"><input type=\"text\" size=\"3\" name=\"qty[{$row['product_id']}]\" value=\"{$_SESSION['cart'][$row['product_id']]}\" /></td>
<td align=\"right\">$" . number_format ($subtotal, 2). "</td>
</tr>\n";
} // End of the WHILE loop.

// Print the footer and close the table and the form.
echo ' <tr>
<td colspan="4" align="right"><b>Total : <b></td>
<td align="right">$' . number_format ($total, 2) . '</td>
</tr>
</table><div align="center"><input type="submit" name="submit" value="Update My Cart" /></form><br /><br /><a href="checkout.php"><font size="+3">Continue To Purchase</font></a></div>';

mysql_close(); // Close the database connection.

} else {
echo '<p>Your cart is currently empty.</p>';
}

?>
<PRE><?php
print_r($_SESSION);
?></PRE>

Now stop arguing and just do as we said.

[elle_girl]

SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id IN (pid) ORDER BY category.last_category ASC

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in C:\Program Files\Apache Group\Apache2\htdocs\view_cart.php on line 58

[bodzan]

The problem really is in query:

SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id IN (pid) ORDER BY category.last_category ASC

pid means nothing to MySQL. If you wanted it to be a value as a string it has to be quoted with single quotes (')...

If you need it to be a number then something went wrong because clearly you don't have a number there...

Forgive Roger on his harsh words, but he has the point: the code is just too hard to analyze when it is not printed with PHP highlighting...
Again, to learn how to use VB code that allows you to do it go here...

Even if it is a small part of code, but to have this large part of code just printed out, it's impossible to see everything...
It may be O.K. for you to look at it, because you wrote it, but for us - it is hard and many won't even bother...

[elle_girl]

// Retrieve all of the information for the prints in the cart.
$query = 'SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id IN (";

[COLOR=red]//The error says at this line[/COLOR] foreach ($_SESSION['cart'] as $key => $value) {
	[COLOR=blue]$query .= $key . ',';
}[/COLOR]
[COLOR=green]$query = substr ($query, 0, -1) . [COLOR=red]"[/COLOR]) ORDER BY category.last_category ASC';[/COLOR]
[COLOR=orange]echo $query;[/COLOR]
[COLOR=green]$result = mysql_query ($query);[/COLOR]

I make changes on the red colour. The previous script it uses single quote but when try use double quote appear this problem

Parse error: parse error in C:\Program Files\Apache Group\Apache2\htdocs\view_cart.php on line 37

[Roger_Ramjet]

You do not want the NAME of the variable ($key) you want the VALUE ($value). Try this

// Retrieve all of the information for the prints in the cart.
$query = "SELECT * FROM category, product WHERE category.category_id = product.category_id AND product.product_id IN (";

foreach ($_SESSION['cart'] as $key => $value) {
$query .= $value . ",";
}
$query = substr ($query, 0, -1) . ") ORDER BY category.last_category ASC";
echo $query;
$result = mysql_query ($query);

[Roger_Ramjet]

I personally prefer explicit joins as they make it more portable as many db engines are stricter with their SQL syntax; and the USING form makes it more obvious what is going on,

// Retrieve all of the information for the prints in the cart.
$query = "SELECT * FROM category INNER JOIN product USING (category_id) WHERE product.product_id IN (";

foreach ($_SESSION['cart'] as $key => $value) {
$query .= $value . ",";
}
$query = substr ($query, 0, -1) . ") ORDER BY category.last_category ASC";
echo $query;
$result = mysql_query ($query);

I kid myself that it will also execute faster: maybe someone can tell me otherwise.

[elle_girl]

After I try the suggestion one that got use INNER JOIN.
It's appear this problem

Notice: Undefined index: 1 in C:\Program Files\Apache Group\Apache2\htdocs\view_cart.php on line 67

Notice: Undefined index: 1 in C:\Program Files\Apache Group\Apache2\htdocs\view_cart.php on line 75

Line 67

$subtotal = $_SESSION['cart'][$row['product_id']] * $row['price'];

Line 75

<td align=\"center\"><input type=\"text\" size=\"3\" name=\"qty[{$row['product_id']}]\" value=\"{$_SESSION['cart'][$row['product_id']]}\" /></td>

Please help me to figure out this problem!

[tsinka]

Hi,

how does $_SESSION['cart'] look now with

print_r($_SESSION['cart']);

Thomas