DAX the Way - with Power BI
DAX stands for Data Analysis eXpressions and it is the formula language used in Power BI. It's similar to Excel formulas and it's an extremely powerful language for creating measures and calculated fields within your Power BI data model. The downside is that it requires a bit of a learning curve to get up to speed. There are a lot of great resources out there for learning DAX and to help us along the April release of Power BI Desktop included a preview feature called Quick measures.
Quick measures allow us to quickly and easily create common and powerful calculations. A Quick measure generates the DAX for us based on the input provided in a dialog box, then presents the results in the report. Best of all, we can see the resulting DAX formula that will be executed, and use that to expand our knowledge of DAX. Learning by example is always the best way in my book.
We create Quick measures by right-clicking a field in the Fields well, then selecting Quick measures from the menu that appears. Also, we can right-click any value in the Values pane of an existing visual. There are 6 categories of calculation types with a number of calculations for each. As of July 2017, the Quick measure feature is still in "preview" mode, so to see it, we have to enable it. Select File > Options and Settings > Options > Preview Features, then select the checkbox beside Quick measures. Restart Power BI Desktop after you make the selection.
When creating a Quick measure, a menu will pop up which guides us through the creation of the specific measure. It's a little confusing at first but after a little trial and error things start to make sense.
Another cool thing is that there's a Quick Measures Gallery in the Power BI community site where DAX experts have shared some advanced DAX snippets. These community contributions often make it into the Power BI Desktop Quick measures menu in future PBI Desktop releases.
So give Quick measures a try and soon we'll all be singing "DAX the way. Uh huh, Uh huh. I like it!".
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