custom cart working out discounts

[mupparion]

Hi,

 

What i want is relatively simple yet i seem to be massively over complicating it.

I've never really had to use forums for help before but this is annoying me now lol.

 

Basically, what i want is when someone orders 3 or more products that aren't in this case, a canvas, they get 20% off the cheapest 3 products.

But where things get complicated is that there is also a quantity field. So if someone orders say 1 item at 1.99 and then 3 at 2.99 id have to be able to get 1.99 + 2 lots of 2.99 and then work out the 20% on that. And obviously i dont know what they're going to order so it needs to be something dynamic and i've kinda written rules for several possibilities but i cant get it right.

 

Heres my code so far anyway:

 

$row3 = mysql_fetch_array(mysql_query("SELECT SUM(qty) FROM `ypc_cart` WHERE `sessid`='$sessid' AND `type`!='canvas' ORDER BY `price` ASC LIMIT 3"));
$price3 = mysql_fetch_array(mysql_query("SELECT SUM(price) FROM `ypc_cart` WHERE `sessid`='$sessid' AND `type`!='canvas' ORDER BY `price` ASC LIMIT 3"));

$row2 = mysql_fetch_array(mysql_query("SELECT SUM(qty) FROM `ypc_cart` WHERE `sessid`='$sessid' AND `type`!='canvas' ORDER BY `price` ASC LIMIT 2"));
$price2 = mysql_fetch_array(mysql_query("SELECT SUM(price) FROM `ypc_cart` WHERE `sessid`='$sessid' AND `type`!='canvas' ORDER BY `price` ASC LIMIT 2"));

$row1 = mysql_fetch_array(mysql_query("SELECT SUM(qty) FROM `ypc_cart` WHERE `sessid`='$sessid' AND `type`!='canvas' ORDER BY `price` ASC LIMIT 1"));
$price1 = mysql_fetch_array(mysql_query("SELECT SUM(price) FROM `ypc_cart` WHERE `sessid`='$sessid' AND `type`!='canvas' ORDER BY `price` ASC LIMIT 1"));

$totalqty3 = $row3['SUM(qty)'];
$totalnonec=mysql_num_rows(mysql_query("SELECT * FROM `ypc_cart` WHERE `sessid`='$sessid' AND `type`!='canvas'"));
/////IF QTY FROM 3 ITEMS IS MORE THAN 3 OR IS 3
if($totalqty3 > 3 && $totalnonec == 3){
echo "3 > 3";
}elseif($totalqty3 == 3  && $totalnonec == 3){
$otherdiscount = (($price3['SUM(price)'] + 0.03)  * 3) * 0.2;


/////IF QTY FROM 2 ITEMS IS MORE THAN 3 OR IS 3
}elseif($row2['SUM(qty)'] > 3  && $totalnonec == 2){
$otherdiscount = (($price2['SUM(price)'] + 0.03)  * 3) * 0.2;
}elseif($row2['SUM(qty)'] == 3  && $totalnonec == 2){
$otherdiscount = (($price2['SUM(price)'] + 0.03)  * 3) * 0.2;

/////IF QTY FROM 1 ITEM IS 3 OR LESS
}elseif($row1['SUM(qty)'] > 2  && $totalnonec == 1){
$otherdiscount = (($price1['SUM(price)'] + 0.03)  * 3) * 0.2;
}else{
$otherdiscount = 0.00;
}

$totaldiscount = $otherdiscount;

 

$otherdiscount = (($price3['SUM(price)'] + 0.03)  * 3) * 0.2;

This is basically, get the price total, add 3p (as all prices end in .99 so it rounds it off) x 3(as you get 20% off 3 items) then x 0.2 to get the 20% value.

 

Probably worth starting over but id have know idea where to begin lol so any help with getting this code to work or posting some new code on where to start would be brilliant!

 

Thanks in advance.

[trq]

Not even going near your question, you are aware that all those queries (7 of them) could be done in 1 simple query?

 

Sorry, but that is some of the worst code/logic Ive seen in a long while.

[mupparion]

Im aware theres probably a way but thats why im on here trying to get the answer to that.

 

I know it is pretty bad and id laugh at it myself if i saw it lol but i just cant get my head round it!

 

Would you mind enlightening me on such a way?