MySQL - 比较列中的所有值并写入另一列

I need to create a script that compares one field in the database (has a date stored, it's type is "TEXT" and cannot be changed DATE) to the current server date.

The dates are encoded like this "1380571547", so i need to use strftime() to decode them. This field for example, decoded with strftime corresponds to this "Sep-30-2013, 22:05"

What I need is to compare those fields with the current date, and according to that condition, write something like "Expired" in another field.

To achieve this, I made this block of code:

<?php
require("connection.php");

$today = strftime('%b-%d-%Y, %H:%M');
$exp_date = mysql_query("SELECT numbers FROM date");

while($row = mysql_fetch_array($exp_date))
{
echo (strftime ( '%b-%d-%Y, %H:%M', $row ['numbers'])). "<br />";
}


if ($exp_date < $today) {
 $sql = "INSERT INTO date (changed) VALUES ('EXPIRED')";
 $result = mysql_query($sql);
 echo "ADDED!";

} 

?>

However, this code is not working, can someone help me ?

You can do all this in a single query:

UPDATE `date` set `changed`='Expired' where date(now()) > date(from_unixtime(`numbers`))

But this is not what your code is attempting to do. Your second block seems to be inserting the word Expired in new rows, rather than updating anything.

Note that the table name date should be wrapped in backticks to avoid any possible clash with MySQL keywords

I don't understand the second block of code with the insert. I would do an update inside the loop. but if your going to do that, it could probably be done in one combined update statement.

PHP is not my strong point but it looks to me like you condition is doing a comparison on an array,

IE:

if ($exp_date < $today) // will always be false.

Your code would probably have to look something more like this.

while($row = mysql_fetch_array($exp_date))
{
   if ($row[0] < $today) 
   {
      $sql = "Update date set changed = VALUE where rowid = rowid";
      $result = mysql_query($sql);
      echo "ADDED!";
    } 
}

having said that i would probably do the comparison and update in SQL using a case statement,

Update Date 
     set changed = case when number > ExpiryDate 
                        then "Expired"  
                        else "Current" 
                        end