Book Image

Expert Data Modeling with Power BI

By : Soheil Bakhshi
Book Image

Expert Data Modeling with Power BI

By: Soheil Bakhshi

Overview of this book

This book is a comprehensive guide to understanding the ins and outs of data modeling and how to create data models using Power BI confidently. You'll learn how to connect data from multiple sources, understand data, define and manage relationships between data, and shape data models to gain deep and detailed insights about your organization. In this book, you'll explore how to use data modeling and navigation techniques to define relationships and create a data model before defining new metrics and performing custom calculations using modeling features. As you advance through the chapters, the book will demonstrate how to create full-fledged data models, enabling you to create efficient data models and simpler DAX code with new data modeling features. With the help of examples, you'll discover how you can solve business challenges by building optimal data models and changing your existing data models to meet evolving business requirements. Finally, you'll learn how to use some new and advanced modeling features to enhance your data models to carry out a wide variety of complex tasks. By the end of this Power BI book, you'll have gained the skills you need to structure data coming from multiple sources in different ways to create optimized data models that support reporting and data analytics.
Table of Contents (18 chapters)
1
Section 1: Data Modeling in Power BI
4
Section 2: Data Preparation in Query Editor
10
Section 3: Data Modeling
13
Section 4: Advanced Data Modeling

Adding a custom column

In my experience, adding a new column is one of the most common steps that we take during the data preparation phase. There are countless scenarios where we need to add a new column, such as adding some new analytical equations as a new column, creating data clusters in a new column, adding an index column as a new column, or using some machine learning (ML) and artificial intelligence (AI) algorithms. You may also have many other scenarios in mind. Whether we use the Power Query Editor UI or manually write the Power Query expressions, we must add a custom column using the following function:

Table.AddColumn(Table as table, NewColumnName as text, ColumnGenerator as function, optional ColumnType as nullable type)

In the Table.AddColumn() function, we have the following:

  • Table: This is the input table value, which can be the result of the previous step or other queries that provide table output.
  • NewColumnName: This is quite self-explanatory &...