I'm looking to write a SQL Query to get the Customers that made only one order after the first of March. So if they ordered twice after the first of March I want to exclude them.
I have the following data extensions.
OrdersDE (this is the DE with all orderes so if a Customer would have ordered on the first of March and second of March would be two orderDates)
I have created a third DE with the following fields
This is what I have so far
SELECT a.customerID, a.FirstOrderDate, b.OrderDate from [MainDE] a left join [OrdersDE] b on a.customerID = b.customerID and [FirstOrderDate] > DATEADD(hh, 7, '01 March 2020')
where count(b.customerID) = 1?