Which of the following is not a valid SQL command?

Group of answer choices

UPDATE acctmanager SET amedate $=$ SYSDATE WHERE amid $=\text{'}$J$500\text{'}$;

UPDATE acctmanager SET amname $=$ UPPER$($amname$)$;

UPDATE acctmanager SET amname $=$ UPPER$($amname$)$ WHERE amid $=\text{'}$J$500\text{'}$;

UPDATE acctmanager WHERE amid $=\text{'}$J$500\text{'}$;