PHP - Get And Compare Rows From Three Tables

I have a cart script, and I need to display the products the user has added.  This is a school assignment and I'm very stuck on this seemingly 'little' error.

Right now, I have two tables:

For time's sake, I am showing duplicate products with different prod_id's:
Table: products
prod_id category sub_category thumb_href image_href title desc summary manufacturer price 17 sofa leather red_leather_sofa_small.jpg red_leather_sofa_main.jpg Red Leather Sofa [BLOB - 134B] [BLOB - 59B] Balenty 999.99 18 sofa leather red_leather_sofa_small.jpg red_leather_sofa_main.jpg Red Leather Sofa [BLOB - 134B] [BLOB - 59B] Balenty 999.99 19 sofa leather red_leather_sofa_small.jpg red_leather_sofa_main.jpg Red Leather Sofa [BLOB - 134B] [BLOB - 59B] Balenty 999.99
And this is the cart table that holds temporary cart items (storing the product ID to pull later):
Table: cart
temp_cart_item cart_id (assigned by session_id() ) prod_id user_id 22 jier11u0e7cl2ghosjodpaark2 17 asdfasdf 23 jier11u0e7cl2ghosjodpaark2 17 asdfasdf 24 jier11u0e7cl2ghosjodpaark2 35 asdfasdf 25 jier11u0e7cl2ghosjodpaark2 5 asdfasdf 26 jier11u0e7cl2ghosjodpaark2 19 asdfasdf
SO, user 'asdfasdf' is logged in and has selected 5 items for his cart - two of which are the same (prod_id 17).  Basically,

I need to compare the prod_id's of each table and output all products (and quantities) matching the temporary cart prod_id.

What I have now to loop through and display the cart items are (bear with me):


echo "<h1>Cart</h1>";
}
// Display welcome and navigation links
displayWelcome();
displayNav();

// Getting the prod_id's from the table cart to compare with the product table
$cart_id = session_id();
$user_id = ($_SESSION['login_username']);
$query = "SELECT prod_id FROM cart WHERE cart_id='$cart_id' AND user_id='$user_id'";
$result = mysqli_query($cxn,$query) or die("<h2 class=\"warning\">Whoa! Problem with the cart script here!</h2>");
$nrows = mysqli_num_rows($result);
if($nrows < 1)
{
echo "<h2>Your cart is empty</h2><p><a href=\"catalog.php\">Go back to the catalog</a></p>";
}
else {  // Continue to gather products for all the product IDs in the products DB table...
echo "<h4>$nrows items in your cart</h4>";
while($row = mysqli_fetch_array( $result )) {
$user_id = ($_SESSION['login_username']);
$product = $row['prod_id'];

// Is the query my problem?
$query = "SELECT * FROM products WHERE prod_id='$product'";
$result = mysqli_query($cxn,$query) or die("<h2 class=\"warning\">Whoa! Problem with the cart script here!</h2>");
$nrows = mysqli_num_rows($result);
if($nrows < 1) { // If the item doesn't exist, display an error
echo "<h2>That is not a valid product, or any of the items you had in your cart are missing or have been deleted.</h2><p><a href=\"catalog.php\">Go back to the catalog</a></p>";
// Protect from continually displaying an error by deleting the invalid cart record
$deletequery = "DELETE FROM cart WHERE prod_id='$product'";
$deleteresult = mysqli_query($cxn,$deletequery) or die("<h2 class=\"warning\">Whoa! Problem with the cart script here!</h2>");
exit();
}
while($row = mysqli_fetch_array( $result )) {  //  Then disply them in a table
echo "<h2>Items in Your Cart:</h2>";
echo "
<table id=\"products\">
<thead>
<tr>
<th class=\"col1 headercol\" scope=\"col\">Thumbnail</th>
<th class=\"col2 headercol\" scope=\"col\">Summary</th>
<th class=\"col3 headercol\" scope=\"col\">Manufacturer</th>
<th class=\"col4 headercol\" scope=\"col\">Price</th>
</tr>
</thead>

<tbody>\n";
$query = "SELECT SUM(price) FROM products WHERE prod_id='$product' GROUP BY price";
$priceResult = mysqli_query($cxn,$query) or die("<h2 class=\"warning\">Whoa! Problem with the cart script here!</h2>");
// keeps getting the next row until there are no more to get
// Print out the contents of each row into a table
echo "<tr>
<td class=\"col1\">"; 
echo "<a class=\"imgHref\" href=\"detail.php?prod_id=".$row['prod_id']."\" title=\"".$row['title']."\"><img src=\"../images/".$row['thumb_href']."\" alt=\"".$row['title']."\" /></a>";
echo "</td>\n"; 
echo " <td class=\"col2\">"; 
echo "<h3 class=\"title\"><a href=\"detail.php?prod_id=".$row['prod_id']."\" title=\"".$row['title']."\">".$row['title']."</a> <span class=\"inlineh3\">by <a href=\"categories.php?manufacturer=".$row['manufacturer']."\" title=\"View all products by ".$row['manufacturer']."\">".$row['manufacturer']."</a></span></h3>";
echo "<p class=\"summary\">".$row['summary']."</p>
<p class=\"descHeading\">&#38;#9758; <em>Full Description:</em></p>
<p class=\"desc\">".$row['desc']."</p>";
echo "</td>\n"; 
echo " <td class=\"col3\">"; 
echo "<p class=\"manufacturer\"><a href=\"categories.php?manufacturer=".$row['manufacturer']."\" title=\"View all products by ".$row['manufacturer']."\">".$row['manufacturer']."</a></p>";
echo "</td>\n"; 
echo " <td class=\"col4\">"; 
echo "<p class=\"price\">$".$row['price']."</p>";
echo "</td>
</tr>\n"; 
}
while($priceRow = mysqli_fetch_array( $priceResult )) {
echo "<tr class=\"short\"><td class=\"col1\"><h3><a href=\"clear_cart.php\">Empty Cart</a></h3></td><td class=\"col2\"></td><td class=\"col3 nobackground\">Total:</td><td class=\"col4\">$".$priceRow[0]."</td></tr>";
}
echo "</tbody>
</table>";
echo "<p class=\"submitOrder\"><form action='submit_order.php' method='post' id='form'>
  <input type='submit' name='pButton' value='Submit Order'>
  <input name='order_total' type='hidden' id='order_total' value='".$priceRow[0]."' />
</form>
</p>";
}
}



And so the cart.php looks something like this (this example asdfasdf has 6 items in his cart):



So you can see that it only displays ONE item, even though asdfasdf DOES have 6 items in his cart (proven by checking database).  And the price is not accurate, either.

Can anyone help me in where my problem might be?  Is it my query?  Or my while clause?

Hi everyone!
I've been looking for a solution, but i just can't find it anywhere...

Ok, so the problem is:
i have a database which looks something like this:

user_id product_id score
14 . 235 . 79
23 . 235 . 32
53 . 665 . 21
14 . 235 . 90
5 . 675 . 45


This is step-by-step of what i need to do:

1. Select user - user_id =343

2. For user_id =343 select all products that he gave score to:
product_id = 43 - score = 99
product_id = 12 - score = 56
product_id = 68 - score = 32
product_id = 124 - score = 67

3. Find all users that voted for the same products e.g.:
for product_id = 43:
user_id = 125 voted 93 points,
user_id = 23 voted 56 points.


4. Calculate the difference between the score of user, so:
for product_id = 43:
user_id = 125 voted 93 points (99 - 93 =6 points of diff.)
user_id = 23 voted 56 points (99 - 56 =43 points of diff.)
return the results....


That's basically what i need to do. I still don't know the number of the users, or product, but it doesn't really matter - i just need to make it work.
Ok, hope someone can help!

Hi!
I have two similar  tables on two different databases and i need to check if there are any entries on the table1, for example, that there aren't on the second table and print if there are i need to print them.
Any suggestions?
Thank you...

Hi guys! Once again i require your endless talents!

I have 2 tables in my mysql DB. One table is a list of products a store offers, the other is the cart of the user. I need to find the most efficient way or retrieving the images and prices from the LIST OF PRODUCTS table based on the list of PRODUCT NUMBERS stored in the cart table of the user.

List of products offered

*************************
Prod # * Price *      img src     *
*************************
001     * 19.99* imgs/pic1.jpg *
002    * 29.99 * imgs/pic2.jpg *
*************************

User's Cart
*********************
Prod # * quantity * size *
*********************
001     *    10       *  m    *
002     *     4        *  s     *
********************

Basically i just want to retrieve ONLY the rows that i need (ones that the user has added to his/her cart) and ASSOCIATE the img src with the quantity and size so that i can lay it out in a table on a view_cart page...

If you want a good laugh just take a look at what ive done so far...

Code: [Select]
$cart = mysql_query("SELECT * FROM ".$session."");

$cart_row_count = mysql_fetch_assoc($cart);
$cart_row_count = mysql_num_rows($cart_row_count);

if($cart_row_count != 0){

$i = 1;

while($cart_result = mysql_fetch_assoc($cart)){
${"product$i"} = $cart_result['product'];
${"size$i"} = $cart_result['size'];
$i++;
}

$i2 = 1;

$query = "product = ".${"$product$i2"}." ";

while($i2 <= $i){
$i2++;
$query .= "AND ".${"$product$i2"}." ";
}
}

Hey Guys,

I'm struggling with some logic of how to do something wondering if anyone can point me in the right direction.

Details:
I am making a PHP/MySQL game to learn more PHP, I've got my login/logout system created. However I am planning on the game been map based on a 100x100 grid. I have two tables:

USERS
Username, Password, x, y
Test, Test, 1, 1


MAP
X, Y, type
0,1,1
0,2,1
0,3,2
0,4,3
0,5,2
etc

I am stuck on how to get the user's logged in X and Y coordinates and then compare them with the map table X and Y, to see what type of field to show, 1,2 or 3.

Is there a name for this type of function so I can do some research on it? Or could someone give me an example? Would be fantastic if anyone has any advice.

Thanks in advance
NewcastleFan