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

Grouping data

In this section, we will learn how to group data from a table within Excel Power Query by specifying columns to group by and select the operation to perform as a new column. Group By in Power Query is very much like the Group By option in SQL.

We will use the SalesData1 query to group the region and find the sum aggregate of sales for each region:

  1. Select the SalesData query in Power Query and duplicate it. Rename the query SalesGroup.
  2. Click on Home | Group By.
  3. We will first complete a Basic example. Click on the drop-down list located directly under Basic and make sure Region is selected. Set New column name to RegionSales and choose an operation to perform. The column to select to obtain the total sales for each region would be Sales in this case:
    Figure 5.47 – Group By dialog box

    Figure 5.47 – Group By dialog box

  4. Click on OK to view the result:
    Figure 5.48 – Result of sum of sales per region

    Figure 5.48 – Result of sum of sales per region

  5. Let's see how the Advanced Group By feature works. This time, import...