> I'm trying to make a page to help in detecting people using automatic
> refresher programs.  In the table that stores user info, there is a
> column called "lastseen" which says when the user was last seen.  I'm
> trying to:
> 1. Select all lastseen colmns that are less than 5 minutes old
> 2. Wait 2 seconds
> 3. Select lastseen columns that have changed since step 1, and display
> that info
> Any ideas on how to do this?  Is it even possible?  Thanks...

Temp tables would probably work great here... I'm assuming mysql, but
the logic should work with any db. 

//untested code:

$result = mysql_query("CREATE TEMPORARY TABLE temp (PRIMARY KEY (id))
SELECT id, lastseen FROM table WHERE lastseen > NOW() - INTERVAL 5


$result = mysql_query("SELECT table.* FROM table, temp WHERE table.id =
temp.id AND table.lastseen != temp.lastseen");

Then parse the results of the second query and it should give you those
rows that have changed in 2 seconds. 

---John Holmes...

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