Re: need help with some aggregation magic

The ts means the time the user started on a project ?
Or the time he finished?
Or can mean both? If so, how do you can tell one from the other? Different 
event_type s ?
Is it correct to assume from your words that an user cannot be in more than 
one project at the time? If so, can't be overlapping, right?

Best,
Oliveiros

----- Original Message ----- 
From: "Andreas" <maps.on@gmx.net>
To: <pgsql-sql@postgresql.org>
Sent: Thursday, June 09, 2011 2:43 PM
Subject: [SQL] need help with some aggregation magic


> hi,
> I have a log-table that stores events of users and projects like this
> ( user_id integer, project_id integer, ts timestamp, event_type integer )
>
> I need an aggregated list of worktime per user, per project, per day.
>
> The users can switch projects during the day so I can't work this out with 
> min(ts) and max(ts).
>
> Is there a clever way to get this with SQL ?
>
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