题解 | #实习广场投递简历分析(三)#

select a.job,a.date1 as first_year_mon,a.cnt as first_year_cnt,
b.date1 as second_year_mon,b.cnt as second_year_cnt
from (select job,left(date,7) as date1,sum(num) as cnt
from resume_info group by date1,job)a
join
(select job,left(date,7) as date1,sum(num) as cnt
from resume_info group by date1,job)b
on right(a.date1,2)=right(b.date1,2) and a.job=b.job
where a.date1 like "2025%" and b.date1 like "2026%"
order by first_year_mon desc,a.job desc

分组算出每月的简历，2025\2026分开，根据工作和月份相等连接，俩排序