And since a picture tells more than a thousand words, let’s look at these four tiny tables where the first two columns are calculated somehow in the third column. It sounds far more complicated than it is. Self-referring? Recursive? What are you talking about? When it was introduced long ago, it probably was the Tableau dream of everyone who fell in love with loops and recursive functions in other tools or languages. PREVIOUS_VALUE is a self-referring function. Ready? Let’s get right into it and do the boring theory at the beginning (so we don’t have to bring it up later when it gets exciting). So, what does this function do? There is no better way to learn something than to teach it, so here is a new blog that reduces a five-year learning path down to 15 minutes. That does the trick.) Three Foundational Principles ![]() ![]() (To show previous values, just use the LOOKUP function with an offset of -1. And let’s get one thing straight right away: If you want to show the previous values of your field, don’t bother with this function because that’s the very thing it can’t do. Have a guess at when I finally understood the PREVIOUS_VALUE function … It was yesterday. ![]() ![]() You know what? I have been working with (and teaching) Tableau for over five years.
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