How do you build a list of unique items in a field?

[Marinus]

I'd like to build up a list of unique user id's that call a service.
If I use eval to just concatenate the next user id, I'd end up with duplicates.

eval userids=userid+","+userid

[ziegfried · Accepted solution]

You could use multivalue fields:

 ... | stats values(userid) as userids | eval userids=mvjoin(userids,",")

[Marinus]

I ended up using eventstats rather than stats, thanks Ziegfried!