Book Image

Learn Power Query

By : Linda Foulkes, Warren Sparrow
Book Image

Learn Power Query

By: Linda Foulkes, Warren Sparrow

Overview of this book

<p>Power Query is a data connection technology that allows you to connect, combine, and refine data from multiple sources to meet your business analysis requirements. With this Power Query book, you’ll be empowered to work with a variety of data sources to create interactive reports and dashboards using Excel and Power BI. </p><p>You’ll start by learning how to access Power Query across different versions of Excel and install the Power BI engine. After you've explored Power Pivot, you’ll see why Excel users find it challenging to clean data in Power Pivot and learn how Power Query can help to tackle the problem. The book will show you how to transform data using the Query Editor and write functions in Power Query. A dedicated section will focus on functions such as IF, Index, and Modulo, and creating parameters to alter query paths in a table. You’ll also work with dashboards, get to grips with multi-dimensional reporting, and create automated reports. As you advance, you'll cover the M formula language in Power Query, delve into the basic M syntax, and write the M query language with the help of examples such as loading all library functions offline in Excel and Power BI. Finally, the book will demonstrate the difference between M and DAX and show how results are produced in M. </p><p>By the end of this book, you’ll be ready to create impressive dashboards and multi-dimensional reports in Power Query and turn data into valuable insights.</p>
Table of Contents (17 chapters)
Free Chapter
1
Section 1: Overview of Power Pivot and Power Query
6
Section 2: Power Query Data Transformations
11
Section 3: Learning M

Creating calculated measures

In this section, we will learn when to use the calculated measure feature and how to create a new measure by adding a function or expression. Let's look at some of the things we need to know before creating a calculated measure.

All measures need to contain a function. A measure cannot work without the table column you are creating the measure on having a function (sum, min, count, and so on) within the formula—this is the difference between a calculated column and a calculated measure. This is called an aggregator (function), and without an aggregator, it is called a naked column in the programming world. IntelliSense is very useful here as it will complete your code for you.

The beauty of measures is that they are only calculated when they are accessed, and so they don't use up your memory. They also allow many different outputs to be produced by just changing the filter criteria of the existing measure. Measures are created in...