在Postgres中展平JSONB数组 [英] Flattening JSONB array in postgres

问题描述

我正在使用Postgres 9.4并将数据存储为JSONB数组.我正在寻找一种方法来提取数组内的json元素，并使用psql将它们替换为一个串联的json元素.以下表为例:

I am using Postgres 9.4 and storing my data in as JSONB arrays. I am looking for a way to extract json elements inside the array and replace them with one concatenated json element using psql. Consider as example following table:

'aaa' | [{"a":"foo"},{"b":"bar"},{"c":["baz", 'boom']}]  | 404
'bbb' | [{"bar":"foo"}]                                  | 501

我想要实现的是:

'aaa' | {"a":"foo", "b":"bar", "c":["baz", "boom"]}     | 404
'bbb' | {"bar":"foo"}                                   | 501

我尝试使用内置的json类型的postgres函数来实现它.但是我只想出了如何在确切位置提取元素. 提前致谢.

I have tried to achieve it using builtin postgres functions for json types. But I only figured out how to extract elements at the exact position. Thanks in advance.

推荐答案

SELECT  id, jo.obj
FROM    mytable
CROSS JOIN
        LATERAL
        (
        SELECT  JSON_OBJECT_AGG(jt.key, jt.value) obj
        FROM    JSONB_ARRAY_ELEMENTS(data) je
        CROSS JOIN
                LATERAL JSONB_EACH(je.value) jt
        ) jo

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