Creating a data model
The concept of a data model or dataset is fundamental to Power BI. In short, a data model is defined by the tables that are created from Power Query queries, the metadata (data about data) regarding the columns within the tables, and finally, the relationships that are defined between tables. Relationships are needed to connect individual tables to one another. In Power BI, the data model is stored within an Analysis Services tabular cube. It is the creation of this data model that enables self-service analytics and reporting.
In Chapter 4, Connecting to and Transforming Data, we connected to various sources of data (three different Excel files) that in turn created seven different queries, which ultimately resulted in four queries that loaded data tables into our data model. We will now stitch those individual tables, along with our previously created data table, into a cohesive data model that can be used for further analysis.