slanoss

In my original I have Insert into table1 (time) values ($ti); which works correctly (no quotes round $ti) I have put insert into table1 (time, time2) values ($ti, $ti - interval 1 hour ); But it doesn't work, NULL is inserted into time2 not time minus 1 hour Any ideas , thanks.

I insert a time value using the following code $ti= ( !empty($_POST['time']) ) ? "'{$_POST['time']}'" : 'NULL'; I want to insert a second time value into a differen column which would be the same time minus 1 hour something along the lines of : $ti2= ( !empty($_POST['time']) ) ? "'{$_POST['time'] -1 hour}'" : 'NULL'; What would be the correct way to do it