I have a question about how to build rollup formula.
My database is tracks members for my organization and which programming events they attend in each program year. I have a member table linked to an events table. I want to build a rollup formula that will count how many unique members attend each event. That is to say, I want to know how many people who have attended each event are people who have not yet attended any other events in the program year.
I have built a column in the members sheet that pulls out the earliest event date that members have attended. In the events sheet for each event (each entry row), I want the rollup to count how many records in the continuum file have the earliest date that matches the event date in that row. How can I do this?