题解 | 获取有奖金的员工相关信息。

select *, case when btype = 1 then (salary)*0.1
               when btype = 2 then (salary)*0.2
               when btype = 3 then (salary)*0.3
               end as bonus from(
select t1.emp_no, t1.first_name, t1.last_name, t2.btype, t3.salary from
employees as t1 
inner join 
emp_bonus as t2
inner join 
salaries as t3
on t1.emp_no = t2.emp_no and t1.emp_no = t3.emp_no
where t3.to_date = '9999-01-01') as t4