You could do a recursive CTE by passing the start date and stopping at the end date (with the where clause), with the other fields being null or zero (with their castings). Then, just do a union all with the results of this CTE and the original table in the target query. Bingo! The blank months will be there.

Nice Kata! But it would be even better if the instructions were showing the limits of the integer values. It is a bit annoying to have submissions failing because of not knowing the maximum value.

Thanks for consuming a whole week of my life!

This challenge was simply amazing and I was able to learn a lot by solving it.

My regards to you Mr(s) Voile.