$1)$ Alter table dept add column dep$\_$phone number$(5)$;

$2)$ Alter table dept drop dep$\_$phone;

$3)$ Select count $*$ from customer;

$4)$ Update employee emp$\_$name$=$Jack where dep$\_$no$=119$;

$5)$ Delete $*$ from employee;

$6)$ Select empno, empname from emp$\_$susan where empno$=!150$;

$7)$ select depno, max$($salary$)$ from emp$\_$susan order by depno group by depno;