By the end of this chapter you will be able to:

• Create macros
• Use macros

Creating macros

1. Find  Macros in the repository.
2. Expand it and click  macro.
3. Configure the macro:
   1. Name: NumOfWeeks
   2. Minimum Parameters: 2
   3. Maximum Parameters: 2
   4. Expression: create an expression to work out the number of weeks - as a whole number – between two dates
      1. Use the functions dateDiff() and round() to help with this
4. Press  OK to save your new macro

Using Macros

1. Create a new model: Try Macros
2. Drag the Table MC Macro Terminated Customers on to your model. This contains some key dates for terminated customers: the signup date; the date that the customer terminated their service; the date that the final debt on the customer's account was cleared
3. Add attributes for:
   1. the number of weeks between signup and termination
   2. the number of weeks between termination and the final debt being cleared
4. In each case, use your macro to calculate the number of weeks between the two dates
5. Run the stream MC Macro Terminated Customers to test your new attributes