Report showing comparison for sales per month this year vs. last year

This is not easy to do, so the solutions depend on the nature of what you are trying to summarize.  The issue is that you cannot natively do arithmetic calculations on columns in a summary report.

If, for example, you just wanted grand totals for the whole Company year over year, then you would need ot load up a table of say the next 20 years, set the Key field to be the year and then using summary fields get to totals you need up to that record.  Then you can do all the math you like.  

If these were totals by say Customer, then you would need to have summary fields such as say YTD sales this year, and YTD sales last year (say to the most recently completed month) and then do the math on the customer record.

This seems like it should be a function of Qbase and be much easier than this. I can't be the only person who wants to compare old data.

This is easy to do with script. But your question is very broad without any reference to the desired report format, what is being aggregated or fields involved. Without regard to native QuickBase capabilities post a mockup of what you want the summary report (or chart) to look like and what fields are involved.

I had the exact same issue & was pretty confused by the previously posted "solutions".  But I came up with a MUCH easier solution for this. 

To make a Bar Chart, you can do the following:

• Create a Chart Report & select Bar Graph
• Immediately create a custom report field (I called it "Months").  This will be a number formula field - formula you will post is simple:
         Month(ToDate([Date Created]))
• 
  Set X Axis to your custom field, set Y Axis to whatever you are trying to summarize (I just did a count field), and set the series to Date Created, grouped by Year

Here is the final product:




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Monster Monster
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