Assume that the following table is created and stored in your database:
staff (staff_no, name, position, salary, sex, job_id, hire_date)

write sql statements to do the following:

a. increment the salary of managers by 5%;
b. delete the records of all 'salesmen' from the staff table;
c. delete the record for the staff whose name is 'smith' and staff number is 17.
d. insert a new staff < 18, 'johnson', 'salesman, 2500, 'f'> in the database.
e. update the salaries for all staff who have one of the job ids similar to those in department 5.