英文:
Postgresql - How to query nested array elements
问题
我在PostgreSQL 13表中有一个JSON数组数据。我想查询这个表，以查看输出中的所有嵌套数组数据。我尝试了下面的查询，但它没有提供预期的输出。
select
json_data::json -> 'Rows' -> 0 -> 'Values' ->> 0 as Lid
,json_data::json -> 'Rows' -> 0 -> 'Values' ->> 1 as L2LicenseId
,json_data::json -> 'Rows' -> 1 -> 'Values' ->> 0 as Lid
,json_data::json -> 'Rows' -> 1 -> 'Values' ->> 1 as L2LicenseId
from test;
有人能帮帮我吗？
示例数据
CREATE TABLE IF NOT EXISTS test
(
json_data text
);
INSERT INTO test (json_data) VALUES ('{"Origin":"api","Topic":"licenses","Timestamp":"2023-02-07T12:46:42.2568898+00:00","Columns":["LId","L2LicenseId","SfdcAccountId","SfdcLineItemId","SL","Quantity","StartDate","EndDate","DisplayName","ProductPrimaryKey"],"Schema":["string","string","string","string","string","int32","datetime","datetime","string","string"],"Rows":[{"Values":["1234","123456","ACC_","PurchaseT","SKU-0000","1","2023-01-09T00:00:00.0000000","2024-01-08T00:00:00.0000000","Automation with 5 users","lc11dev.my-dev.com"]},{"Values":["8967","8967-e567","fihikelo","Addon_00000490_2nd_GB","SKU-0490","3","2023-01-01T00:00:00.0000000","2023-01-22T00:00:00.0000000","Automation, Data 5GB","mygreattest01311433.my-dev.com"]}]}');
预期输出
英文:
I have JSON array data in PostgreSQL 13 table. I want to query this table to see all the nested array data in the output. I tried the below query, but it's not giving the expected output.
select
json_data::json -> 'Rows' -> 0 -> 'Values' ->> 0 as Lid
,json_data::json -> 'Rows' -> 0 -> 'Values' ->> 1 as L2LicenseId
,json_data::json -> 'Rows' -> 1 -> 'Values' ->> 0 as Lid
,json_data::json -> 'Rows' -> 1 -> 'Values' ->> 1 as L2LicenseId
from test;
Can someone please help me?
Sample Data
CREATE TABLE IF NOT EXISTS test
(
json_data text
);
INSERT INTO test (json_data) VALUES ('{"Origin":"api","Topic":"licenses","Timestamp":"2023-02-07T12:46:42.2568898+00:00","Columns":["LId","L2LicenseId","SfdcAccountId","SfdcLineItemId","SL","Quantity","StartDate","EndDate","DisplayName","ProductPrimaryKey"],"Schema":["string","string","string","string","string","int32","datetime","datetime","string","string"],"Rows":[{"Values":["1234","123456","ACC_","PurchaseT","SKU-0000","1","2023-01-09T00:00:00.0000000","2024-01-08T00:00:00.0000000","Automation with 5 users","lc11dev.my-dev.com"]},{"Values":["8967","8967-e567","fihikelo","Addon_00000490_2nd_GB","SKU-0490","3","2023-01-01T00:00:00.0000000","2023-01-22T00:00:00.0000000","Automation, Data 5GB","mygreattest01311433.my-dev.com"]}]}')
Expected Output
答案1
得分: 1
您可以使用PostgreSQL函数jsonb_array_elements（或json_array_elements）来执行此操作。该函数提取所有Json数组元素，并将其视为行。
select
a2.value -> 'Values' ->> 0 as Lid,
a2.value -> 'Values' ->> 1 as L2LicenseId
from test a1
cross join jsonb_array_elements(a1.json_data::jsonb->'Rows') a2
结果:
lid | l2licenseid
---- | -----------
1234 | 123456
8967 | 8967-e567
英文:
You can do it using PostgreSQL function jsonb_array_elements (or json_array_elements). This function extracts all Json array elements like as rows view.
select
a2.value -> 'Values' ->> 0 as Lid,
a2.value -> 'Values' ->> 1 as L2LicenseId
from test a1
cross join jsonb_array_elements(a1.json_data::jsonb->'Rows') a2
-- Result:
lid | l2licenseid |
--- -+-------------+
1234 | 123456 |
8967 | 8967-e567 |
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