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

招聘及二手房数据分析
https://www.yuque.com/hdms/kuo8zy/qhohqcslg5fcd1ox?singleDoc#

hive教程
https://github.com/sfzsjx/document_classfication/blob/master/%E5%A4%A7%E6%95%B0%E6%8D%AE%E6%8A%80%E6%9C%AF%E6%A0%88/%E6%95%B0%E6%8D%AE%E5%AD%98%E5%82%A8/hive/hive-%E5%B0%9A%E7%A1%85%E8%B0%B7.md

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;