Thank you for your response. Not sure what happen to my question below. I need to put the number one in the minimum date for that customer id.

example
4/3/2019 23456 1
6/1/2019 23456 0
9/1/2019 23456 0
4/20/2018 34567 1
10/1/2018 34567 0
5/3/2019 34567 0