Noob query

  I'm pretty new to mySQL. If I have a table with these fields:

userid date action

How would I form a query to count the number of records within the past hour with different userids? That is, I want to find out how many unique users are active in the past hour.

I know how to count all the active records in the past hour: SELECY count(*) FROM records WHERE date >= DATE_SUB(NOW(),INTERVAL 1 HOUR)"

But I want the number of unique user id's in that list. I could get the first list and then iterate through it. That would be fine for an hour, but I want to do the same thing for days and weeks, which would probably not be the best option.

Thanks Received on Wed Jan 07 2015 - 23:06:35 CET