PHP and Comparing Dates, ARGHHH!

_sh

Guys,

I've been using PHP for a few months coming from ASP and have to comment that the date support/confusion in PHP is ridiculous, needs entirely rethinking in my opinion...but anyway!

I'm building a large site and have used MYSQL TimeStamps throughout most of the DB tables.

I'm not listing some results from one of the tables and have dates outputing from MYSQL in this format for example...

2008-11-08 13:35:38

What I want to do is output the contents of the table into PHP, sorted by date order - I then want to list the results for instance in...

TODAY
result row 1
result row 2
result row 3

YESTERDAY
result row 4
result row 5
result row 6

(then to list each day in groups...)

07/11/08
result row 7
result row 8

06/11/08
result row 9
result row 10

Can someone help me to achieve this as I'm completely stuck...not with the looping necessarily but with the date comparison?

Is there no simple 'FormatDateTime' as there is in ASP?

_sh

Just had a crack at this myself...the only test I could come up with is as follows to determine whether its TODAY or not, but its not using Logical date comparison, rather string I guess?...

<?PHP if (substr($RS_GrabHolaLifeStories['StoryDateAdded'],0,10) == substr(date("Y-m-d"),0,10)) { ?>

<div>TODAY</div>

<?PHP } else { ?>

<div>NOT TODAY</div>

<? } ?>

cahva

Well you can do this entirely on the mysql side using mysql's datetime functions. I really dont know what are you saying about confusion in PHP's date support and what are you missing. I dont know asp but php has datetime class that you can use to format the dates as you wish.

$dt = new DateTime('2008-11-08 13:35:38');
echo $dt->format('d/m/y'); // prints 08/11/08

_sh

Ahhh, not seen that Format command before, or the use of the -> ? Could you explain these a little more as the example has confused me somewhat - can you not use format() like this perhaps?

format('2008-11-08 13:35:38',d/m/y)?

cahva

ashleyhall;10892360 wrote:

<?PHP if (substr($RS_GrabHolaLifeStories['StoryDateAdded'],0,10) == substr(date("Y-m-d"),0,10)) { ?>

<div>TODAY</div>

<?PHP } else { ?>

<div>NOT TODAY</div>

<? } ?>

Using datetime class this would be:

$db_date = new DateTime($RS_GrabHolaLifeStories['StoryDateAdded']);
$today = new DateTime();

if ($db_date->format('ymd') == $today->format('ymd')) {
    // Today
} else {
    // Not today
}

Use of -> is for objects. I really dont have time to explain this but look at the PHP manual about classes and objects.

Documentation is a little bit lousy in the manual concerning the DateTime which was introduced in PHP 5. Maybe this article can help you understand it better:
http://laughingmeme.org/2007/02/27/

As I said, you can use also Mysql's date and time functions to get the output you need and even do the comparison in the query itself.

_sh

Thanks matey, perhaps I'll reread this tomorrow with a clear head!!

Weedpacket

You can also compare date/time strings directly if you use the format MySQL returns them in: >, <, ==, and even strcmp() will give the correct results if you use them to compare two strings: e.g., "2008-11-08 13:35:38" > "2008-11-07 13:35:38".

This is a deliberate feature of the format: all the punctuation is exactly the same and in exactly the same positions, so the only bits that differ are the digits; and the components are ordered year-month-day-hour-minute-second, so that the larger the difference is in time the more significant the difference in the string (if the years are different you don't need to look at the months to see which is earlier).