SQL Transform for Customers With No Invoice Dated 2 Years Prior to Current Year
I have developed an ETL dataflow that outputs our gross margins per job. I have then used this dataflow to create cards that show total gross margins by customer. What I am looking for is to start from this exact same ETL flow but output only customers that have not had invoices in the 2 years prior to current year - so currently, that would be 2019 and 2018.
I've tried to create a new ETL transform with the first transform as input but I can't figure out how to filter out the customers that have had invoices in past 2 years. Is this something that must be done through an SQL transform or is there a way through ETL? I am very weak at SQL and just okay at ETL.
|Sample Input Data||Desired Output Data|
|Customer||Job GM||Invoice Date||Customer||Job GM||Invoice Date|