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

Working with extraction tools

At some point, you may have a very large table and need to create a number of separate Power Query tables out of the data source. The extract tool is perfect for this purpose. I need to mention here that there are many methods to achieve this, such as creating a duplicate query, and then deleting the columns you no longer require. We will also use the extract tool to extract the age of a student from a date in the query.

Extracting an age from a date

In this section, you will use Power Query to extract the age of employees from a date column, transform the time format into total year format, and round down the age column.

The first example we will look at is to extract the age of students from an enrolment list:

  1. Import the student data table from SSGSchoolAdmin.accdb into Power Query.
  2. Since the DOB column was converted into the Date/Time format type on import, format the DOB column to the Date data type.
  3. Select the DOB column....