Union vs Union ALL Solution

Hi Osmiguel!

Thanks for reaching out.

Although the solution contains many lines of code, the idea is to "form" several result sets containing the same fields, and vertically combine them together.
More precisely, we have used as an alias for each result set, or each subset, a different letter (A, B, C, D). Then, we combine these subsets.

Hope this helps but please feel free to get back to us should you need further assistance. Thank you.
Best,
Martin