PHP/MySQL sum() works but need sum with multiple fields

[mo]

Hopefully I get at least one response this time.

 

I have a query that returns the total amount of items in a shopping cart:

 

$sqlStr = mysql_query("select SUM(`price`) as total from `mr_cart`

                  WHERE `cart_session_id` = '$sid'") or die(mysql_error());

 

The table mr_cart has two fields, price and quantity. I need to get the total for each line's price * quantity.

 

Anyone???

[cooldude832]

show us some table structure please, odds are it will be better to extract data raw and then  total in post using arrays and a while function

[per1os]

$sqlStr = mysql_query("select SUM(`price` * `quantity`) as total from `mr_cart`
                      WHERE `cart_session_id` = '$sid'") or die(mysql_error());

 

Try that.

[mo]

 cart_id int(11)            

 smid int(11)          

 store_name varchar(40)          

 cart_session_id char(32)              

 cart_qty decimal(10,0)            

 price float              

 cart_date datetime            

 title varchar(40)                

 options longtext            

 comments longtext

 

I was trying to avoid doing the calculation in post processing after the query, for performance reasons. I prefer to do the sum (price * cart_qty) in the query, if possible.

 

Thanks...

[cooldude832]

so i take it there is multiple rows for one cart?  can you give me an example of a cart with saw 3-4 items in it.  I'm not grasping this for some reason and its making me feel stupid

[mo]

Thanks Frost. That did the trick, it works perfectly now.

 

I actually thought of doing it the way you suggest but didn't even try as I thought the syntax was incorrect. I guess I was wrong. I'll experiment next time.