sql练习--给出每个员工每年薪水涨幅超过5000的员工编号emp_no、薪水变更开始日期from_date以及薪水涨幅值salary_growth,并按照salary_growth逆序排列

链接:https://www.nowcoder.com/practice/eb9b13e5257744db8265aa73de04fd44?tpId=82&tqId=29779&tPage=2&rp=&ru=/ta/sql&qru=/ta/sql/question-ranking

分析:
1.计算薪水涨幅必须知道涨薪前的薪水和涨薪后的薪水,故需要两个表,这两个表可以通过复用salaries实现
2.每年 可以是涨薪后的to_date - 涨薪前的to_date = 1或者
涨薪后的from_date - 涨薪前的from_date = 1或者

代码:

select s2.emp_no,s2.from_date,(s2.salary - s1.salary) as salary_growth
from salaries as s1,salaries as s2
where s1.emp_no = s2.emp_no
and (strftime(’%Y’,s2.to_date) - strftime(’%Y’,s1.to_date) = 1
or strftime(’%Y’,s2.from_date) - strftime(’%Y’,s1.from_date) = 1)
and s2.salary - s1.salary > 5000
order by salary_growth desc

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