Count unique assignment IDs when the name matches

BFuller

Hello, I'm struggling with a a cross-sheet formula where I count the number of unique assignments IDs when the name matches. I've tried the following without success:

=COUNTIFS({Assignment ID}, {Name}, [Primary Column]@row)

=COUNTIFS(DISTINCT({Assignment ID}, {Name}, [Primary Column]@row))

=COUNTIF(DISTINCT({Assignment ID}, {Name}, [Primary Column]@row))

=COUNTIFS(DISTINCT(COLLECT({Assignment ID}, {Name}, [Primary Column]@row)))

I keep getting INCORRECT ARGUMENT SET

Can someone help me identify what I am doing wrong?

Paul Newcome

You are close with the last one. You need a COUNTIFS/DISTINCT/COLLECT.