Summary
In this chapter, we covered a lot of ground! We talked a lot about DAX, the programming language to implement business rules in Power BI.
We went over the basics of DAX, how it looks a lot like Microsoft Excel formulas, and how those formulas are applied in either the row or filter context. We compared measures to calculated columns.
We then discussed one of the most powerful functions in DAX, CALCULATE. We used CALCULATE to manipulate the filter context of our formulas to create more complex equations. We saw how CALCULATE can be used with simple filtering or be combined with the FILTER function for more powerful operations.
We discussed date tables and how they can be used with time intelligence calculations and how the date table becomes a role-playing dimension to be used across many related tables. We learned that Power BI includes time intelligence functions to make aggregations such as Year-over-Year much easier.
When comparing measures and columns, we...