The beginnings of M
As we have learned so far, Power Query allows you to connect to data sources, as well as clean, transform, filter and then, finally, publish them. Beyond this, it also allows you to mash up or collate data from multiple sources. The language is called M, as Mashup is the jargon name that it started with.
Power Query has a really good interface that allows most people to use it effectively without doing too much programming. Everything that you create in Power Query is translated into M. Although we have dabbled a bit with M, we have allowed Power Query to do most of the work for us. In Chapter 8, Creating Dashboards with Power Query, we edited M and created our own code when we inserted additional columns. Without M, we would not be able to write more complex queries, transformations, and calculations. There are certain things, such as connecting to web services, that can only be done with custom M code.
The first thing I would like to say is that M is a...