Microsoft Office Tutorials and References
In Depth Information
You might have noticed that the report shows the numbers of the months and not their names,
which surely needs to be fixed. In Chapter 7, “Date Calculations in DAX,” where we cover date
handling in much more detail, you learn how to show the month names. Nevertheless, faster
help comes in Chapter 3, where you find a “Date and Time Functions” section with a list of the
functions available to you for manipulating dates. You also find in Chapter 3 a simple formula
for getting both the number and the name of a month from a date.
The technique of adding more columns to the table to produce aggregates when the data
inside the table is too detailed is frequently used with dates. Moreover, dates are so important
a topic in the BI analysis that we will spend all of Chapter 7 on it. That said, there are many
columns that are not good aggregators. For example, in Chapter 10, “PowerPivot Data Model
Patterns,” you see a complete banding system that performs aggregations by price bands and,
as you will learn, the technique is similar to the one we just used: whenever a column is not a
good aggregator, you need to add new columns that group more data so that aggregated
values get interesting.
Now that we have scratched the surface of some of the many PowerPivot features, it is time
to understand what happens to your reports when the underlying data changes, something
that happens rapidly because of the normal life cycle of data.
A report is nothing but an Excel file with a PivotTable that queries data and provides interesting
results. Our current model is already a good source that produces nice reports like the one
in Figure 2-32. As you might notice, we used the date year and month in columns, so we can
expect this report to change over time.
FIguRE 2-32 A report that contains current dates probably needs to be refreshed periodically.