Varying Percentages Discount Based on Quantity

Hi

I am trying to add a percentage discount to our eCart5 when a user adds 3 of a certain product, BUT some of these products will offer 10% off if you buy 3 and some will offer 20% off and also 50% off....How can this be achieved? also what addition do I have to make in the database?, add another column with the percentage? ie: 20 so if this column has a value then that product has a discount applied to it?

Please can someone assist, need to have this complete over the weekend :o(

Many thanks in advance.

add a column to the cart for the discount percentage. use the decimal value, so 0.1 for 10%, etc. name the column discountPercentage

on the calculations tab, create a calculation named discountAmount as:
abs([Quantity] >= 3)?([Price] * [Quantity]) * [discountPercentage]:0

on the discounts tab, create the discount as:
trigger:
"Subtotal for any column" if the subtotal of column "discountAmount" as ">" a value of "0"

Calculation:
"Based on column subtotal"
subtotal for column "discountAmount" "plus" "0"

Hi Jason

Thanks for a great detailed explanation....but it is throwing up a syntax error in the Cart_PHP.php page on line 12
" $itmObj->discountAmount = abs($itmObj->Quantity >= 3)?($itmObj->Price * $itmObj->Quantity) * [discountPercentage]:0;//t"

Error: Parse error: syntax error, unexpected '['

what did you name the cart column? it should be named discountPercentage

Yes....that is what I named it

send the Cart_PHP.php page file please.

Sent

there is no column named discountPercentage:

//columns
$this->ID = $itemID;//n?
$this->Name = $itemName;//t
$this->Description = $itemDescription;//t
$this->Thumbnail = $itemThumbnail;//t
$this->Weight = $itemWeight;//w
$this->Quantity = $itemQuantity;//n
$this->Price = $itemPrice;//c
//calculations



on the columns click the plus button and add a new column, name it discountPercentage

Output type? Unique?

Output type van be left as text or set to number.

don't select unique.