I m so sorry i just missed this :
Use SUM() in your SQL statement to add a total of a column. SELECT SUM(Price*Quantity) AS TotalPrice FROM orderdetails WHERE OrderID = 1
So Sory again. you already had mentioned solution here.
But how can we update TotalAmount , Discounts, OrderInsurance, OrderTax using that TotalPrice.
I had added the rules in eCart Object. Where can i find the sql formats which are already saved in webassist folder?