RE: [PHP] convertion from string to time & substracting

Umm...How about using UNIX_TIMESTAMP() in your query, then you won't need any of that PHP code you just wrote... ---John Holmes... > -----Original Message----- > From: Erik Price [mailto:pricee@hhbrown.com] > Sent: Friday, June 07, 2002 2:22 PM > To: juaid > Cc: php-general@lists.php.net > Subject: Re: [PHP] convertion from string to time & substracting > > > On Friday, June 7, 2002, at 02:01 PM, juaid wrote: > > > sorry if maybe this is a bit dumb question, but I'm a begginer with > > php... > > > > I got a mysql database, where two of the fields of a table record times > > as > > CHAR(8) in the format hh:mm:ss > > > > I want to take this two times and get the difference between them in > > seconds, for example 12:01:30 - 12:00:00 = 90 > > I looked up at the doc in the php.net website and couldn't get on how > > to do > > this... should I use the strtotime function? > > > > anyone has donde something like this, or knows what functions could > > help me > > to do this? > > First of all, if you're storing time then you're better off using the > DATETIME column type. Even though it may take a bit more space than > CHAR(8), unless you absolutely need the ultimate in table optimization, > use DATETIME. It makes comparisons and manipulations like the one you > are trying to do much easier. (Because you can convert them to > UNIX_TIMESTAMP and then do your math on that, which is a piece of cake.) > > But to answer your question, here's what I would do: > > // $db contains database connection handle > $sql = "SELECT row FROM table WHERE where_clause"; > // attempt to pull data from DB > if (!$result = mysql_query($sql, $db)) { > die('Query failed.'); > } > > // assuming only one row is returned > $row = mysql_result($result, 0); > > $time_array = explode(':', $row); > $hours = $time_array[0]; > $minutes = $time_array[1]; > $seconds = $time_array[2]; > > // convert to timestamp so we can easily do math > $timestamp = mktime($hours, $minutes, $seconds, 0, 0, 0); > > Now all of your times are in timestamp form, and you can do what you > need to do. > > > > Erik > > > > > ---- > > Erik Price > Web Developer Temp > Media Lab, H.H. Brown > pricee@hhbrown.com > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php