Page 719 - Excel 2013 All-in-One For Dummies

Using the PowerPivot and Power View Add-Ins 701
For more on data modeling with PowerPivot for Excel
Being able to establish relationships between data tables in Diagram View represents just a small part of PowerPivot’s data modeling capa- bilities. To find out more about data modeling
with PowerPivot for Excel 2013, be sure to review the online help topics by selecting its Help button in the PowerPivot window.
To make it easier to draw the line that creates the relationship between two data tables with a shared key field, you should position the tables near one another in the Diagram View. Remember that you can move the data table graphic objects around in the PowerPivot window simply by dragging them by their title bars.
Adding calculated columns courtesy of DAX
DAX stands for Data Analysis Expression and is the name of the language that PowerPivot for Excel 2013 uses to create calculations between the col- umns (fields) in your Excel Data Model. Fortunately, creating a calculation with DAX is more like creating an Excel formula that uses a built-in function than it is like using a programming language such as VBA or HTML.
This similarity is underscored by the fact that all DAX expressions start with an equal sign just like all standard Excel formulas and that as soon as you start typing the first letters of the name of a DAX function you want to use in the expression you’re building, an Insert Function–like drop-down menu with all the DAX functions whose names start with those same letters appears. And as soon as you select the DAX function you want to use from this menu, PowerPivot not only inserts the name of the DAX function on the PowerPivot Formula bar (which has the same Cancel, Enter, and Insert Function buttons as the Excel Formula bar), but also displays the complete syntax of the func- tion, showing all the required and optional arguments of that function imme- diately below the Formula bar.
In addition to using DAX functions in the expressions you create for calcu- lated columns in your Data Model, you can also create simpler expressions using the good old arithmetic operators that you know so well from your Excel formulas (+ for addition, – for subtraction, * for multiplication, / for division, and so on).
Book VII Chapter 2
Generating Pivot Tables