Convert MySQL timestamp field to a Unix timestamp

Question

I have a process where I want to compare the current date with an expiration date that is so many months after a registration date. The registration date is stored in a MySQL timestamp format. I want to convert this to a Unix timestame so I can do the comparison with Time(). I have tried both the MySQL UNIX_TIMESTAMP and the PHP getTimestamp() functions and cannot get them to work. I have tried UNIX_TIMESTAMP both in  the original SELECT statement and as a stand alone one. I also get a divide-by-zero error with the date_default_timezone_set function. I have enclosed screenshots of the code and the result of the echo at the bottom. THANKS!

Answer 1

You're making it far too complicated.
SELECT TO_DAYS(reg_date) - TO_DAYS(CURDATE()) AS daysleft
FROM ssregis
WHERE. . .
That will give you the number of days left until the registration expires. If it's less than 0, redirect to the renewal page.
By the way, you're laying yourself wide open to SQL injection attacks by failing to escape the input from the query string. At the very least, you should be doing this:
$entered_ss_id = mysql_real_escape_string($_GET['record_id']);
$entered_email = mysql_real_escape_string($_GET['email_address']);
However, since it looks as though you're hand-coding the script, you should be using MySQL Improved rather than PHP's deprecated MySQL functions. See http://docs.php.net/manual/en/mysqlinfo.api.choosing.php.