CODEWITHSUNDEEP
mysqlsql
Mawg
Mawg

Reputation: 40140

A counting problem

I have a table with columns user_id, time_stamp and activity which I use for recoding user actions for an audit trail.

How can I COUNT the number of unique user_id where time_stamp=0 when there might be multiple such rows, differing only in in the activity text?

Upvotes: 0

Views: 68

Answers (2)

jmoreno
jmoreno

Reputation: 13561

select count(*) 
FROM (select t.user_id, count(*) actions
      FROM table t
      where t.time_stamp = 0
      group by t.user_id) u

Should do it for you (not the most straightforward way, but it shows how to do a couple of different things).

Upvotes: 1

OMG Ponies
OMG Ponies

Reputation: 332561

Sounds like you need to use:

  SELECT COUNT(DISTINCT t.user_id)
    FROM YOUR_TABLE t
   WHERE t.time_stamp = 0
GROUP BY t.activity

Upvotes: 4

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