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

Shortcomings of Power Pivot

There are a couple of limitations of Power Pivot-driven pivot tables that you need to recognize so that you can work out if you can use them or the internal data model.

Problem 1 – selecting multiple items

The first issue is with trying to group dates into quarters or years. You could Select Multiple Items and then select the relevant dates that you wanted, but this is very time-consuming. Also, it is likely that human error could occur, as you might miss-click on one of them:

Figure 2.38 – Date problem with Power Pivot

Figure 2.38 – Date problem with Power Pivot

Problem 2 – Power Pivot preview

The second problem is that in a standard pivot table, you can double-click on a cell and then see all the rows that make up that amount in that cell. In Power Pivot tables, you can only see the first 1,000 rows:

Figure 2.39 – First 1,000 rows problem with Power Pivot

Figure 2.39 – First 1,000 rows problem with Power Pivot

Problem 3 – calculated fields

The...