with tb1 as(
    select emp_no, salary
    from salaries
    where to_date='9999-01-01')

select emp_no, first_name, last_name, btype, salary, 
case when btype=1 then round(0.1*salary,1)
when btype=2 then round(0.2*salary,1)
else round(0.3*salary,1) end as bonus
from tb1 right join emp_bonus using(emp_no)
left join employees using(emp_no)
order by tb1.emp_no