Hopefully someone can point me in the right direction, since I'm sure this problem has been asked to death already, but I just can't find the answers...
I have 2 worksheets in a workbook: "Orders" and "History". Both sheets contain the exact same columns. The "Orders" page data gets wiped clean at the start of each month. What I'm looking for is a macro solution that will copy any new rows and update any old ones that have changed on the "Orders" page to the "History" page, so we can keep a running history of sales. Ideally, I'd like the macro to fire only when performing a Workbook Save or Workbook Save As.
"History" is in date order, so adding new entries from "Orders" should be easy, just by adding rows to the bottom. Updating existing rows will be harder, because I want it to update if the row has changed but not be deleted or changed when the "Orders" sheet is wiped clean the 1st of the month. Any ideas?
Additional:
The columns in both sheets are:
Order Date
Ship Date
Order Number
Customer
Item
Qty
Amount
Because each item gets a seperate line, there will be rows that have identical Order Date, Ship Date, Order Number, and Customer entries, so I suspect I will need to compare multiple columns when deciding if one has changed (the only column that *should* change after initial entry on the orders page is the Ship Date, which would initially be left blank when the order is first entered).