Re: look for latest user login in one table from a list of

On Fri, 14 Mar 2003, Sill-II, Stephen wrote:

> I'm trying to come up with an efficient way to do the following task, but I
> haven't found the correct join syntax to do it.
> 
> I have table "users" for keeping a list of users I need to check logins for.
> It contains the following fields:
> 
> id,Full-Name,User-Name
> 
> I have table called "logs" that contains the actual radius log data.  The
> three fields I am concerned with are:
> 
> User-Name,Date,Time
> 
> I have gotten thus far almost what I want with the following query.
> 
> SELECT users."User-Name",max(logs."Date") as login_date,max(logs."Time") as
> login_time FROM logs where logs."User-Name"=users."User-Name" GROUP BY
> users."User-Name";

Try
foo=# SELECT users.name,someq.mlast from users left outer join (select 
id,max(last) as mlast from log group by id) as someq using(id);

substituting with your names.

> 
> This gives me the User-Name, date, and time of people WHO HAVE LOGGED IN.
> I'm looking to have a query that returns all of the users in the first
> table, including those who have not logged in.  I have an external perl
> script that generates a nice html report for the manager.  I have a script
> that parses the raw .csv files, but I'm trying to move it entirely to
> postgres, including if possible stored-procedures in plperl.  I already have
> a perl script that imports the raw log files into the logs table.
> 
> Am I on the right track?
> 
> Thanks,
> 
> Stephen Sill II
> 
> 
> 
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Achilleus Mantzios
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