<-- case "字段" when "条件" then "符合条件的值" else "不符合条件的值" end !--> select dept_id, sum(case sex when ‘男‘ then 1 else 0 end), sum(case sex when ‘女‘ then 0 else 1 end) from emp_sex group by dept_id
Hive练习题
原文：https://www.cnblogs.com/HYBG-JXMD/p/14933389.html
