Hive 将单个 Integer 列分成多行答案

【问题标题】：Hive Divide single Integer column into multiple rowsHive 将单个 Integer 列分成多行
【发布时间】：2021-10-29 02:14:44
【问题描述】：

我在 Hive 中有 3 列的表，我想根据特定值划分最后一列（在我的情况下为 200） Hive 表结构：-

ID ,Name ,Value 
1,"Jan",800
2,"Mar",200
3,"DEC",350
4,"APR",400

我希望输出为

ID ,Name ,Value 
1,"Jan",200
1,"Jan",200
1,"Jan",200
1,"Jan",200
2,"Mar",200
3,"DEC",200
3,"DEC",150
4,"APR",200
4,"APR",200

我尝试使用侧视图爆炸，但没有给我正确的结果

【问题讨论】：

标签： sql hive hiveql

【解决方案1】：

ceil(value/200) 给出为给定值生成的行数。您可以使用split(space(...)) + lateral view posexplode 生成行，然后使用posexplode返回的位置来计算当前值。

演示：

with mytable as (--demo dataset, use your table instaed of this CTE
select 1 ID,"Jan" Name,800 Value union all
select 2,"Mar",200 union all
select 3,"DEC",350 union all
select 4,"APR",400
)

select id, name, 
       --value 200 is hardcoded in many places, you can pass it as a parameter to the script
       case when (pos+1)*200 > value --remains less than 200
               then value-pos*200 
            else 200 
       end as value
from
(
select id, name, value, int(ceil(value / 200)) num_rows 
  from mytable
)s  
 --generate string of space, split it and posexplode  
 lateral view outer posexplode(split(space(num_rows-1),'')) e as pos, x

结果：

id  name    value
1   Jan      200
1   Jan      200
1   Jan      200
1   Jan      200
2   Mar      200
3   DEC      200
3   DEC      150
4   APR      200
4   APR      200

【讨论】：