Dany Hoter shows how to use Power Query to join one row to the next in a data set (given similar criteria) and do day-by-day comparisons:
I want to analyze the daily prices of certain commodities and be able to show the patterns of daily changes side by side. I want to calculate predictably the differences between each row and the row before. Each row represents data for a day, so the difference between rows is the daily change or in some cases, several days change.
I downloaded from Quandl 50 years of daily prices of gold and silver, and my goal is to calculate the daily changes in terms of dollars and percentage from day to day. Not all days are represented, so in case of a gap I calculate the number of days in the gap, and I divide the growth % by the number of days. I already imported and appended the data for both metals into a single table in Excel and we’ll start the process from this table.
Read on for the solution. I’d just as soon LAG() the data in SQL Server, but if that’s not an option, this certainly works.