如何在 Hive 中提取嵌套的 JSON 对象

Question

我有一个名为“影响”的列，其中包含嵌套 Json 格式的数据

输入： [{"internalid":"079","impactid":[{"position":"1","typeid":"NOEUD","value":"G1"},{"position":"2","typeid":"ID","value":"001"},{"position":"3","typeid":"CODE_CI","value":"14"}],"typeid":"BTS","cdrs":"X110","belong":"OF","impactclass":"R","count":"0","numberaccessimpacted":"0","impactcalculationrequest":null},{"internalid":"6381075","impactid":[{"position":"1","typeid":"NOEUD","value":"G3"},{"position":"2","typeid":"ID","value":"003"},{"position":"3","typeid":"CI","value":"58"}],"typeid":"BTS","cdrs":"X110","belong":"OF","impactclass":"R","count":"0","numberaccessimpacted":"0","impactcalculationrequest":null},{"internalid":"6381071","impactid":[{"position":"1","typeid":"NOEUD","value":"G2"},{"position":"2","typeid":"IDT","value":"002"},{"position":"3","typeid":"CI","value":"57"}],"typeid":"BTS","cdrs":"X110","belong":"OF","impactclass":"R","count":"0","numberaccessimpacted":"0","impactcalculationrequest":null}]

我使用下面的代码：

SELECT 
       get_json_object(single_json_table.identifiant, '$.position') AS impact_position,
       get_json_object(single_json_table.identifiant, '$.value')  AS impact_value
   FROM 
   (SELECT exp2.identifiant
  FROM  socle s
  lateral view explode(split(regexp_replace(substr(impact, 2, length(impact)-2),
          '},\\{"', '},,,,{"'), ',,,,')) exp2 as identifiant   
           )single_json_table 

这是结果，它跳过了第一个位置和值，有人知道我该如何解决吗？

impact_position  |  impact_value
(null)                (null)
2                     001
3                     14
(null)                (null)
2                     003
3                     58
(null)                (null)
2                     002
3                     57 

Answer 1

您的输入是带有嵌套数组的 JSON。上层数组是整个输入，包含 struct > >, impactid 是一个嵌套数组，包含这样的结构元素：{"position":"1","typeid":"NOEUD","value":"G1"}

您需要分解两个数组。先分解上层数组：改变分隔符，拆分，分解，然后对嵌套数组做同样的事情。

演示：

with socle as (
select '[{"internalid":"079","impactid":[{"position":"1","typeid":"NOEUD","value":"G1"},{"position":"2","typeid":"ID","value":"001"},{"position":"3","typeid":"CODE_CI","value":"14"}],"typeid":"BTS","cdrs":"X110","belong":"OF","impactclass":"R","count":"0","numberaccessimpacted":"0","impactcalculationrequest":null},{"internalid":"6381075","impactid":[{"position":"1","typeid":"NOEUD","value":"G3"},{"position":"2","typeid":"ID","value":"003"},{"position":"3","typeid":"CI","value":"58"}],"typeid":"BTS","cdrs":"X110","belong":"OF","impactclass":"R","count":"0","numberaccessimpacted":"0","impactcalculationrequest":null},{"internalid":"6381071","impactid":[{"position":"1","typeid":"NOEUD","value":"G2"},{"position":"2","typeid":"IDT","value":"002"},{"position":"3","typeid":"CI","value":"57"}],"typeid":"BTS","cdrs":"X110","belong":"OF","impactclass":"R","count":"0","numberaccessimpacted":"0","impactcalculationrequest":null}]'
as impact

)

select internalid,
       get_json_object(e.impact, '$.position')  as position,
       get_json_object(e.impact, '$.value')  as value
from
(
select get_json_object(impacts, '$.internalid') internalid,
      --extract inner impact array, remove [], convert delimiters 
       regexp_replace(regexp_replace(get_json_object(impacts,'$.impactid'),'^\\[|\\]$',''),'\\},\\{','},,,,{') impact
from 
(
SELECT --First we need to explode upper array. Since it is a string, 
       --we need to prepare delimiters to be able to explode it
       --remove first [ and last ], replace delimiters between inner structure with 4 commas
       regexp_replace(regexp_replace(s.impact,'^\\[|\\]$',''),'\\},\\{"internalid"','},,,,{"internalid"') upper_array_str 
  FROM  socle s
)s lateral view explode (split(upper_array_str, ',,,,')) e as impacts --get upper array element
)s lateral view explode (split(impact, ',,,,') ) e as impact

结果：

internalid  position    value
079         1          G1
079         2          001
079         3          14
6381075     1          G3
6381075     2          003
6381075     3          58
6381071     1          G2
6381071     2          002
6381071     3          57