将先前的请求值与当前值php mysql进行比较

Question

Well i have a page, which gets refreshed EVERY second. For every request, a random value will be generated and will be sent to the server.

$random_number = $_REQUEST['rand'];

This is my scenario - For every second, i will have a random value. I need to pull greater value by comparing with the previous value(from previous request)

time(seconds)   random values   considered value  
    1                 5               5    // 5 > null or 0. so it is 5
    2                 1               5    // 1 < 5. so it is 5
    3                 6               6    // 6 > 1. so it is 6
    4                 4               6    // 4 < 6. so it is 6
    5                 2               4    // 2 < 4. so it is 4
    6                 4               4    // 4 > 2. so it is 8

And for every request, i need to run UPDATE query, for whichever my considered values are greater than previous values.

EDIT - How do i run UPDATE query based on the greater value considered every time?

Answer 1

you can do below changes in your php file

$random_number = $_REQUEST['rand'];
if(isset($_SESSION['random_number']) && $_SESSION['random_number']>0) // check wether last random number is available in session, (i.e for first run there will be no previous random number)
{
     $old_random_number = $_SESSION['random_number'];
     // do your comparison and mysql update queries here
}
$_SESSION['random_number'] = $random_number; // update the session variable with new random number

dont forget to put session_start() on the top of your PHP page..

let me know if any help needed.