hive 时间相减

  select  

   case when  "2017-01-18 23:59:56" > substr("2017-01-18 23:59:55.511" ,1,19)    

        then  unix_timestamp("2017-01-19 00:00:00")  - unix_timestamp(substr("2017-01-18 23:59:55.511" ,1,19))

        else   "cuowu"

        end    

   from  xxxxxx.xxxxxxxx where dt='20170112' limit  10;