select distinct emp_no,
        first_name,
        last_name,
        btype,
        salary,
        CASE WHEN btype = 1 THEN salary * 0.1
        WHEN btype = 2 THEN salary * 0.2
        ELSE salary * 0.3
        END bonus
from employees join emp_bonus using(emp_no) left join salaries using(emp_no)
where to_date="9999-01-01"
order by emp_no