go back by one in select statement

[cretaceous]

can I do this with one query - its to show "last time user logged in"

I've been doing

$tlsql="SELECT MAX(in_tdate) as logintd FROM user_session WHERE u_id='$currmemid' GROUP BY u_id";

but that returns the current log in time
I want one log in back ..

which I guess means I need to do
$tlsql="SELECT in_tdate as logintd FROM user_session WHERE u_id='$currmemid' ORDER BY n_tdate DESC LIMIT 2";
then I'm looking at the second row returned

Hmm perhaps I've answered my own question

any comments?

[ixalmida]

If you are looking for the exact TIME of the last login, I think you may have the right idea. But if you aren't concerned about today's logins, you could simply eliminate today's date:

$tlsql="SELECT MAX(in_tdate) as logintd FROM user_session ".
  "WHERE u_id='$currmemid' AND DATE(in_tdate) < CURDATE()";

OR - if this is happening right after a login, you could just eliminate logins in the past 10 seconds or so:

$tlsql="SELECT MAX(in_tdate) as logintd FROM user_session ".
  "WHERE u_id='$currmemid' AND in_tdate < NOW() - 10";

[Bjom]

Yes, but why use workarounds that are error-prone, when the LIMIT variant just works fine?

You need LIMIT 1,1 actually to get only the 2nd entry:

$tlsql="SELECT in_tdate as logintd FROM user_session WHERE u_id='$currmemid' ORDER BY n_tdate DESC LIMIT 1,1";

[ixalmida]

Because LIMIT is slower - and how are my suggestions "error-prone"? I tested both queries before I posted them and they worked just fine. Maybe they don't suit the intended purpose, but there are no errors nor do they fetch the wrong data.

[Bjom]

the second is error-prone because you could still eliminate the one that you actually want to see