Rolling unique person count by month over a time period
600493Sep 28 2007 — edited Sep 29 2007Anyone have any idea how I could get a rolling count of the unique number of people that have purchased from a single query?
Month Person
Jan-07 A
Jan-07 B
Feb-07 A
Feb-07 C
Mar-07 D
Desired Output when run for Jan-March
Month Count
Jan-07 2
Feb-07 3
Mar-07 4