Creating new data

Hi guys,

I have dataset that gets created as part of an ETL.

I would like to take a copy of this data remap one of the columns and then append it to the original set. Something like below.

So take the data add a customer Id column default to say 1.

Duplicate the data. Remap the customer Id column to something else and append.

So essentially I end up with 2 copies of the data in one set with different customer ids.

How can this be achieved?

I want it all to end up in the same dataset so don't want to run another ETL doing this.

Thanks