4 replies to this topic

[rannt]

Hi!

I'm working on a simple shopping cart, and I have problems with suming prices. Now I'm using this:

$query = "SELECT SUM(price) FROM cart WHERE sid='$sid'"
?>

This returns prices sum of all products with the same session id, BUT in table cart I also have field quantity. How can I get the quantity for every field and multiply it withe the price? And in the end of course get the sum of all prudct prices?

I hope you understand me

[rc69]

$sql = mysql_query("SELECT quantity, price FROM cart WHERE sid='$sid'");
while($r = mysql_fetch_assoc()){
  $total += $r['quantity']*$r['price'];
}

I assume that's fairly close to what you want done.

[rannt]

Quote

Warning: Wrong parameter count for mysql_fetch_assoc() in /www/specialci/razred/trgovina/izpis_izdelkov.php on line 37

If I use this:

$sql = mysql_query("SELECT quantity, price FROM cart WHERE sid='$sid'");
while($r = mysql_fetch_assoc($sql)){
$total += $r['quantity']*$r['price'];
}

it returns

Quote

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /www/specialci/razred/trgovina/izpis_izdelkov.php on line 37

Please help!

[rc69]

Dang it... i knew i forgot something from that.
Anyway, try this

$sql = mysql_query("SELECT quantity, price FROM cart WHERE sid='$sid'") or die(mysql_error());
while($r = mysql_fetch_assoc($sql)){
  $total += $r['quantity']*$r['price'];
}

That error should help you figure out what's going wrong with the mysql_query()

[rannt]

OMG, I'm so stupid I added mysql_error and found out, that field price is missing
Thank you for your help!

Edited by rannt, 26 September 2005 - 10:22 AM.