I;ve figured it out myself with the help of some online articles.

Hi Mike,

I have changed

WITH latest AS (SELECT ROW_NUMBER() over(PARTITION BY product_code, ORDER BY date_price DESC) AS RowNumber,product_key ,price

...

Hi Mike,

Thanks so far, but the query returns the message

Msg 207, Level 16, State 1, Line 19

Invalid column name 'product_code'.

Hi Mike,

Thanks for your reply. Yes, I want a new row for every sale since the price has changed.

Please allow me to give you an example.

The price for product A...