select e.emp_no,e.first_name,e.last_name,b.btype,s.salary,
     case b.btype when 1 then s.salary*0.1
                  when 2 then s.salary*0.2
                  else s.salary*0.3
                  end bonus
from employees e , emp_bonus b , salaries s 
WHERE e.emp_no=b.emp_no
AND e.emp_no=s.emp_no
and s.to_date='9999-01-01'
;
  1. 注意再sql中不能直接使用10%,要转换为小数
  2. 注意观察表格,dept_emp表格没有被创建
  3. 注意to_date的要求
select e.emp_no,e.first_name,e.last_name,b.btype,s.salary,
    case b.btype when 1 then s.salary*0.1
                      when 2 then s.salary*0.2
                      else s.salary*0.3
                      end bonus
from employees e join emp_bonus b 
    on e.emp_no=b.emp_no
join salaries s    
    on e.emp_no=s.emp_no
where s.to_date='9999-01-01'
;