Working with Web Services in Power Query

One of many cool things about Power Query is the way that it allows you to retrieve data from web services and load it into Excel. While this is a subject that lots of people (including me) have already blogged about, the Web.Contents() function – which is the M function that you’ll need to use to call a web service in your query – has gained some new, useful functionality over the last few releases that isn’t fully documented anywhere and which is important to know about.

For this post I’ll use a real-life example of a web service that I’ve been working with recently. As you may know, I’m one of the organisers of SQLBits and a few weeks ago I was given the task of building a Power BI solution to monitor registrations. SQLBits uses RegOnline to handle registrations and they have an API that allows developers…