ALLEXCEPT is a handy DAX function to retrieve all the columns of a table except for some. When used as a CALCULATE modifier, its behavior is less intuitive and might result in inaccurate measures. In this video, we elaborate on the most common mistake when using ALLEXCEPT in CALCULATE.
Article and download: https://sql.bi/31031?aff=yt
How to learn DAX: https://www.sqlbi.com/guides/dax/?aff=yt
The definitive guide to DAX: https://www.sqlbi.com/books/the-definitive-guide-to-dax-2nd-edition/?aff=yt