题解 | #获取有奖金的员工相关信息。#

#学习在select里使用case when else end结构。
select eb.emp_no,e.first_name,e.last_name,eb.btype,a.salary,
CASE WHEN eb.btype==1 THEN a.salary*0.1 
        WHEN eb.btype==2 THEN a.salary*0.2 
        ELSE a.salary*0.3
END as bonus
from emp_bonus eb left join
(select emp_no,salary
from salaries
where to_date='9999-01-01') as a on eb.emp_no==a.emp_no
LEFT join employees e on eb.emp_no==e.emp_no