Example Workflow for ETL Basics Operations

On sales2008-2011.csv data set a number of ETL operations are performed. Besides showing what ETL features are, the goal of this workflow is to move from a series of contracts with different customers in different countries to a one-row summary description for each one of the customers. The one-row description includes: the customer unique ID; the total amount of money payed by the customer to the company; the countries the customer has been active in; the date of the first contract (this is always useful to estimate the customer loyalty); and the number of days between the first and the last purchase, that is the number of days the customer has been with the company. At the end, each one-row customer summary information will be joined together with each contract data row from the original file and write the resulting table to a CSV file in a "data" folder located in the workflow folder.

This is a companion discussion topic for the original entry at https://kni.me/w/KqH9or10w2ixYb78

I am brand new to this software. I have kind of an elementary question because I’m stuck on the first GroupBy node with a red box around it. There appears to be an error on aggregation. How do I fix this so I can execute the node? Thank you!

Hello @AmyIshmael,

and welcome to KNIME Community!

Did you have any progress with your workflow? I have just downloaded and successfully executed it so wondering did you change input data? If that is the case you’ll need to configure nodes accordingly. And what error message do you get?