3-Hive类型隐式转换

关于string类型只能转换为double数字类型进行排序

case1:

select cast(num as double) as num1

  from (

        select DISTINCT regexp_replace(categories,'\[|\]','') as num

          from table_name

        WHERE dt=20180115

          and categories is not null

      )

ORDER BY num1