arithmetics with timestamp?

[Super Mango]

Hi everubody,

I have a timestamp field in a mysql DB and I want to know how much time
has past since that timestamp.

is it possible?
Say that I have this value in a variable -
1) how do I get the current system timestamp?
2) how do I subtract the first from the second?

Thanks!

[Janwillem Borleffs]

Super Mango wrote:

Say that I have this value in a variable -
1) how do I get the current system timestamp?
2) how do I subtract the first from the second?

If you are only interested in the amount of hours, you could do something
like:

$now = time();
$past = time() - 86400;

print 'The difference between $past and $now = ';
echo ($now - $past) / 3600, ' hours';

Of course, you can narrow this figure down to days (div 86400), hours (div
3600), minutes (div 60) and seconds.

These kind of calculations can also be performed by MySQL. Have a look at
the manual @ mysql.com for more info.
JW

[Super Mango]

thanks!

But the thing is that the value in the DB is kept as YYYY-MM-DD hh:mm
how do I convert that to the "time()" format?

[Dave Kelly]

Super Mango wrote:

Hi everubody,

I have a timestamp field in a mysql DB and I want to know how much time
has past since that timestamp.

is it possible?
Say that I have this value in a variable -
1) how do I get the current system timestamp?
2) how do I subtract the first from the second?

Thanks!

I can show you how to do it at a website down the wire using a bash
script. Should be adaptable to something local and PHP.

TIMESTAMP=$(dat e -d "`lynx -error_file=lynx _error -dump
-connect_timeout =20 $url/timestamp.txt`" +%s)

[Janwillem Borleffs]

Super Mango wrote:

thanks!

But the thing is that the value in the DB is kept as YYYY-MM-DD hh:mm
how do I convert that to the "time()" format?

Per example, with strtotime: http://www.php.net/strtotime

JW

[Gordon Burditt]

>I have a timestamp field in a mysql DB and I want to know how much time

has past since that timestamp.

is it possible?
Yes. Use MySQL to do it.
Say that I have this value in a variable -
1) how do I get the current system timestamp?
now()
2) how do I subtract the first from the second?

timestampdiff() . (requires MySQL 5.0 or greater).
timediff(), but it returns the value in hours, minutes, and seconds.
datediff(), but only the date parts are used.

Gordon L. Burditt

[Pedro Graca]

Super Mango wrote:

But the thing is that the value in the DB is kept as YYYY-MM-DD hh:mm
how do I convert that to the "time()" format?

select UNIX_TIMESTAMP( column) from table;

--
Mail to my "From:" address is readable by all at http://www.dodgeit.com/
== ** ## !! ------------------------------------------------ !! ## ** ==
TEXT-ONLY mail to the whole "Reply-To:" address ("My Name" <my@address>)
may bypass my spam filter. If it does, I may reply from another address!

[Toby Inkster]

Super Mango wrote:

I have a timestamp field in a mysql DB and I want to know how much time
has past since that timestamp.

<?php
// Assume timestamp from database is in $ts.
$then = strtotime($ts);
$now = time();
$diff = $now - $then;
// $diff is the difference in seconds.
?>

--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~ http://tobyinkster.co.uk/contact

[d]

"Super Mango" <li********@gma il.com> wrote in message
news:11******** **************@ o13g2000cwo.goo glegroups.com.. .

Hi everubody,

I have a timestamp field in a mysql DB and I want to know how much time
has past since that timestamp.

is it possible?
Say that I have this value in a variable -
1) how do I get the current system timestamp?
2) how do I subtract the first from the second?

Thanks!

If you're going to be doing the vast majority of your time maths outside
MySQL, you might want to use integers instead of timestamps - you can just
save the unix timestamp in the database, which saves time converting between
MySQL and unix times. And, of course, you can still search/sort using the
unix timestamp...