extract date string: 2000121->2000-12-12

Anon

Hello again,

Yet another problem has arisen:

My guestbook at my site saves the messages in a MySQL database. My question is if it is possible to extract the id (your normal MySQL id) like this :
example:

20010108 to: 2001-01-08

Is such a thing possible at all in PHP?
please help me out here,

mail me,
Niels

[deleted]

What are you talking about, extracting a Date or an ID?

polson

Anything is possible.

If you have a string that is eight characters in length and you want 4-2-2 then something like this (there are many ways) can be done :

<?php

$date = '20010108';

$date = ereg_replace("([0-9]{4})([0-9]{2})([0-9]{2})","\1-\2-\3", trim($date));

print $date; // prints 2001-01-08

See how it works? There are basically three "groups" each within () that you match, each being a number [0-9] and next to that is the lengths in braces {}. Then a bit later those three groups are printed out in the format we choose, which is to put dashes between them. \1 for exampe is the first group of numbers, four characters in length.

There is a great tutorial that will expand this information here :

http://phpbuilder.com/columns/dario19990616.php3

Good luck!

polson

I was a tad bit confused on that too so just played off the shown example. Not sure where the ID plays into this so chose to ignore that part of the question :-)

nielskg

I guess it was a bit confusing, anyway this is indeed what I ment:

$date = ';
$date=ereg_replace("([0-9]{4})([0-9]{2})([0-9]{2})","\1-\2-\3", trim($date));

print $date; // prints 2001-01-08

see, my id columns in my databases are always the date 
but when you want to show that date afterwards, you get something like 20010108......with the code above it seems to show 2001-01-08......anyway, thanx for the help....the code works....

Niels

Anon

YUCK! Why use regular expressions when mysql will do this for you?

select date_format(date_field,'Y-m-d') as fdate from table;

polson

smiles and listens. then ponders. sql sure is pretty useful. also there is a nice tutorial on dates here :

http://www.phpbuilder.net/columns/akent20000610.php3

and more information in here :

http://www.php.net/manual/ref.datetime.php

keep in mind (/me opens ears to self) that if SQL can do it then it'll most likely be much faster of a job.

[deleted]

Indeed sql can do a lot more than most people think. A database is not just a fancy storage unit for variables, it can do hefty calculations and string manipulations too.