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

Understanding Parent-Child hierarchies

The concept of a Parent-Child hierarchy is commonly used in relational data modeling. We have a Parent-Child hierarchy when the values of two columns in a table represent hierarchical levels in the data. Parents have children; their children have children too, which creates a hierarchical graph. Let's continue with an example to understand Parent-Child hierarchies and implement them in relational data modeling. Then, we'll look at the Parent-Child design in Power BI. The following diagram shows a typical Parent-Child graph. Each node of the graph contains an ID and the person's Name:

Figure 10.35 – A Parent-Child graph

We can represent the preceding graph in a data table, as shown in the following screenshot:

Figure 10.36 – Parent-Child graph representation in a data table

We can quickly discover that there is a one-to-many relationship between the ID and ParentID columns...