https://www.yuque.com/hdms/kuo8zy/sfn7pwamxvg82x3t?singleDoc# 《大数据分析实训》 密码：merq

资源链接
http://minio.masheng.fun:15000/s/AlHo

厦门工作数据分析
https://www.yuque.com/hdms/kuo8zy/qhohqcslg5fcd1ox?singleDoc# 《2021厦门招聘数据分析》

整体情况（招聘企业数、岗位数、招聘人数、平均薪资）

select count(distinct company) as `企业数`,
       count(1) as `岗位数`,
       sum(num) as `招聘人数`,
       sum(salary * num) / sum(case when salary > 0 then num else 0 end) as `平均工资`
from job;