It’s easy to get rid of duplicate records with Excel’s Power Query (Get and Transform) BUT … what if you want to do the opposite: keep duplicate/multiple records and delete the single-entries?
There are a few steps. We need to use Group By, Filter, Reference a Query, and an Outer Join.
This video was recorded barside at Cascade Brewing Barrel House in Portland, OR. So, grab yourself a beer and enjoy the video.
For an intro to Get & Transform (Power Query) try my Lynda.com course:
My book: Guerrilla Data Analysis 2nd Edition
My old blog: http://datascopic.net/blog-2-2