题解 | 实习广场投递简历分析(三)

select a.job,a.adate,a.asm,b.bdate,b.bsm from
(select job,date_format(date,'%Y-%m') adate,sum(num) asm from resume_info where year(date) =2025 group by job,adate)  a JOIN 
(select job,date_format(date,'%Y-%m') bdate,sum(num) bsm from resume_info where year(date) =2026 group by job,bdate) b
on substring_index(a.adate,'-',-1) = substring_index(b.bdate,'-',-1) and a.job = b.job
order by a.adate desc,a.job desc
注意点在，已经date_format成年月的数据，不能再使用Year(),Month()等函数，因此用到截取

.