This is the SQL code I am using:
For some reason it deletes all records for the UserID but does not take into account the NOT IN array. I need it to delete only if the user ID = the current user AND the courseID of that user is not in the array..
mysql_query("DELETE FROM tblLinkUserCourse WHERE ((UserID=$CurrentUserID) AND (CourseID NOT IN ({$new_array})))");
1) Remove all unnecessary ()
from query.
2) Check $new_array
contains all your course_id or not and constructed as string. If not constructed as string and comma separated use this code.
$new_array = implode(',', $new_array);
mysql_query("DELETE FROM tblLinkUserCourse WHERE UserID=$CurrentUserID AND CourseID NOT IN ({$new_array})");