Cron PHP Help

[HCProfessionals]

Ok, I've been trying to figure this out for about 4 hours now. What I am trying to do is update log information from one table to another every 30 minutes. Am I doing this correct?

 

<?php
$cron = true;

$userinfo = $db->query( "SELECT * FROM users" );

while ( $pulluserinfo = $db->fetch( $userinfo ) ) {
$one .= "" . $pulluserinfo['uID'] . ""; //uID is from the users table
$two .= "" .$pulluserinfo['Amount=Amount+1000+(TotalAmount*10)']. ""; //Amount & TotalAmount is from the users table
$three .= date("F j, Y, g:i a"); //Putting a date
$db->query( "INSERT INTO systemlog (`User`,`Amount`,`Time`) VALUES ('$one', '$two', '$three')" );
}

$db->close();
?>

[litebearer]

are you getting any error messages? is the data not being entered int to the table? does it work? if not, what about it is not working?