Given a table with the structure: PATIENT $($MRN$,$ Name, Age, VisitDate$),$ which of the following is not a valid SQL command?

SELECT$*$ FROM PATIENT

WHERE Name LIKE $\text{'}$Ja$\%\text{'}$;

SELECT COUNT$($MRN$)$ FROM PATIENT;

SELECT COUNT$(*)$ FROM PATIENT WHERE Age $=30$;

SELECT VisitDate, COUNT$(*)$ FROM PATIENT

GROUP BY VisitDate;

SELECT VisitDate, COUNT$(*)$ FROM PATIENT

WHERE Age $30$;