select update concat in one query?? newbie

[bluecloudburst]

I have admins who can login to view employment applications. I'd like to have a column which indicates the application has been reviewed by each specific admins. Session variable is holding the admin's login user_id. Is it possible to use one query to select and display list of applicants, plus that specific applications have been reviewed by specific admins? Saw a post about using CONCAT and COALESCE, since the 'reviewedby' field will be null at first. Admin can click on applicant's name to review application, that's when I want the 'reviewedby' field to update status. Thanks in advance.

$query = "SELECT * FROM applicants WHERE user_id = {$_GET['uid']};
UPDATE applicantsGII
SET applicants.reviewedby = CONCAT(COALESCE(applicants.reviewedby,''),"$_SESSION['user_id']")";

[urtrivedi]

$query="update applicants set applicants.reviewedby = CONCAT(ifnull(applicants.reviewedby,''),".$_SESSION['user_id'].") where user_id={$_GET['uid']}";

[bluecloudburst]

Thanks, that helped alot!! SOLVED