• 本题解析
    本题考查case....when...then...end语法的应用 和多表联合查询

  • 参考答案

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