select eb.emp_no,e.first_name,e.last_name,eb.btype,s.salary,
(case eb.btype when 1 then s.salary*0.1
                when 2 then s.salary*0.2
                else s.salary*0.3 end) bonus
from emp_bonus eb
left join employees e
on eb.emp_no = e.emp_no
left join salaries s
on eb.emp_no = s.emp_no
where to_date = '9999-01-01'