$sql = "INSERT INTO $shift (fullname, position, age, school, w_age, p_age, class, level, access, prolong, course, loc_course, courseen, loc_courseen, english, check_prakt, check_theory, ozpvlp)
VALUES ('$fullname', '$position', '$age', '$school', '$w_age', '$p_age', '$class', '$level', '$access', '$prolong', '$course', '$loc_course', '$courseen', '$loc_courseen', '$english', '$check_prakt', '$check_theory', '$ozpvlp')
ON DUPLICATE KEY UPDATE fullname = VALUES (fullname),
position = VALUES (position),
age = VALUES (age),
school = VALUES (school),
w_age = VALUES (w_age),
p_age = VALUES (p_age),
class = VALUES (class),
level = VALUES (level),
access = VALUES (access),
prolong = VALUES (prolong),
course = VALUES (course),
loc_course = VALUES (loc_course),
courseen = VALUES (courseen),
loc_courseen = VALUES (loc_courseen),
english = VALUES (english),
check_prakt = VALUES (check_prakt),
check_theory = VALUES (check_theory),
ozpvlp = VALUES (ozpvlp)";