https://blog.csdn.net/sunnyyoona/article/details/62894761
select sum(pitem) from (select map_values(repay_principal) principal from dw.dw_xxx) t lateral view explode (t.principal) ptab as pitem
Lateral View使用指南
原文：https://www.cnblogs.com/0xcafedaddy/p/9560603.html
