“Let” Expressions In M

Chris Webb explains “let” expressions  in M:

In the M language a let expression consists of two sections. After the let comes a list of variables, each of which has a name and an expression associated with it. In the previous example there are three variables: step1, step2 and step3. Variables can refer to other variables; here, step3 refers to both step1 and step2. Variables can be used to store values of any type: numbers, text, dates, or even more complex types like records, lists or tables; here, all three variables return numbers. The Query Editor is usually clever enough to display these variables as steps in your query and so displays then in the Applied Steps pane on the right-hand side of the screen

It’s a look at one of the fundamentals of an interesting language.

Related Posts

Power BI Conditional Formatting and Icons

Matt Allington shows how you can now use icons as the output of conditional formatting in Power BI: Note how the icons above have both shape and colour so you can differentiate between them even if you are colour blind.  This is best practice. You can also change the default formatting to work on the […]

Read More

Power Query FILTER()

Rob Collie takes us through a good use of FILTER() in DAX: The thing both of those formulas have in common is that they are using a measure in the filter argument of the CALCULATE function.  In both examples here, I’ve highlighted the offending measure in yellow. CALCULATE([Sightings per Year], [Avg Sighting Length in Mins]>6) CALCULATE([Sightings […]

Read More

Categories

May 2016
MTWTFSS
« Apr Jun »
 1
2345678
9101112131415
16171819202122
23242526272829
3031