Create an aggregate within one dataset

Hi community,

I'm currently working on a data preparation where i have a dataset that contains 3 columns: CustomerID, Date (yyymm), Invoice ID (see table with example).

ID Date Invoice ID 1 201601 A 1 201601 B 1 201602 C 2 201601 D

The aim is to build an aggregate on this table where ID+Date are keys (there is only one row per ID+Date) and a new field that contains the number of invoices this customer has received for the given date.

For the example in the table it should look as follows:

ID Date # of Invoices 1 201601 2 1 201602 1 2 201601 1

How can this be done in Predictive Analytics? I have tested different approaches with the Data Manager but did not find an easy Aggregate Approach.

Thanks for any hints in advance,

Regards,

Sabrina