Question

I’m coding to search data by compare dateTime. In web form, user input value 2012-06-04 store in $_REQUEST['dateSearch']. I create dateTime object from that:

$dateObj = date_create_from_format("Y-m-d",$_REQUEST['dateSearch']);
$dateParam = $dateObj->format("Y-m");

Then I use $dateParam in sql query to find data

$sql = "
    SELECT *
    FROM `temp` as `t`
    WHERE `t`.`date` LIKE '$dateParam%'
";

Everything is ok, but I’m not sure MySQL alway use only one dateTime format Y-m-d H:i:s.
At here, $dateParam = $dateObj->format("Y-m"); I set default format is “Y-m”. Is the default format never change? I don’t want hard set format Y-m-d H:i:s in code, instead of, I think get format string from system to use is better. How do I get default dateTime format string from mySQL???

Answer 1

You misunderstand, Y-m-d H:i:s
is the ONLY format for datetime data type.

Y-m-d = date
H:i:s = time

That’s why is named as datetime

To change the return format for datetime in mysql,
you can use date_format function in mysql

Such as,

date_format('%Y-%m') = 2012-06