Hive 排序数组列相对于同一表中的其他数组列 [英] Hive sort array column with respect to other array column in same table

问题描述

我在 hive 中有一个表，有 2 列作为 col1 array 和 col2 array.输出如下图

I have a table in hive , with 2 columns as col1 array<int> and col2 array<double>. Output is as shown below

col1                col2
[1,2,3,4,5]         [0.43,0.01,0.45,0.22,0.001]

我想按升序对 col2 进行排序，col1 也应该相应地更改其索引，例如

I want to sort this col2 in ascending order and col1 should also change its index accordingly for e.g.

col1                col2
[5,2,4,3,1]        [0.001,0.01,0.22,0.43,0.45]

推荐答案

分解两个数组，排序，然后再次聚合数组.在collect_list之前的子查询中使用sort对数组进行排序:

Explode both arrays, sort, then aggregate arrays again. Use sort in the subquery before collect_list to sort the array:

with your_data as(
select array(1,2,3,4,5) as col1,array(0.43,0.01,0.45,0.22,0.001)as col2
)

select original_col1,original_col2, collect_list(c1_x) as new_col1, collect_list(c2_x) as new_col2
from
(
select d.col1 as original_col1,d.col2 as original_col2, c1.x as c1_x, c2.x as c2_x, c1.i as c1_i  
 from your_data d
      lateral view posexplode(col1) c1 as i,x
      lateral view posexplode(col2) c2 as i,x
where c1.i=c2.i 
distribute by original_col1,original_col2
sort by c2_x
)s
group by original_col1,original_col2;

结果:

OK
original_col1   original_col2                   new_col1        new_col2
[1,2,3,4,5]     [0.43,0.01,0.45,0.22,0.001]     [5,2,4,1,3]     [0.001,0.01,0.22,0.43,0.45]
Time taken: 34.642 seconds, Fetched: 1 row(s)

Edit: 同一个脚本的简化版本，你可以不用第二个poseexplode，直接使用d.col2[c1.i] as c2_x

Simplified version of the same script, you can do without second posexplode, use direct reference by position d.col2[c1.i] as c2_x

with your_data as(
select array(1,2,3,4,5) as col1,array(0.43,0.01,0.45,0.22,0.001)as col2
)

select original_col1,original_col2, collect_list(c1_x) as new_col1, collect_list(c2_x) as new_col2
from
(
select d.col1 as original_col1,d.col2 as original_col2, c1.x as c1_x, d.col2[c1.i] as c2_x, c1.i as c1_i  
 from your_data d
      lateral view posexplode(col1) c1 as i,x
distribute by original_col1,original_col2
sort by c2_x
)s
group by original_col1,original_col2;

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