snobuilding 一個表，其中包含雪花中鍵值數組中的動態列

Question

我有下表 -

ID , DATA
1   [{"key":"Apple", "value":2}, {"key":"Orange", "value":3}]
2   [{"key":"Apple", "value":5}, {"key":"Orange", "value":4}, {"key":"Cookie", "value":4}]

我想建立下表：

Id, Apple, Orange, Cookie
1   2      3     
2   5      4      4

我嘗試了許多 parse_json 和 flatten 的組合，但似乎沒有一個支持這種結構。

Answer 1

樣本數據：

CREATE OR REPLACE TABLE tab
AS
SELECT 1 ID, PARSE_JSON('[{"key":"Apple", "value":2}, {"key":"Orange", "value":3}]') AS DATA
UNION 
SELECT 2, PARSE_JSON('[{"key":"Apple", "value":5}, {"key":"Orange", "value":4}, {"key":"Cookie", "value":4}]');

第 1 步 - 解析：

SELECT id, s.VALUE:key::TEXT AS key, s.VALUE:value::TEXT AS value
FROM tab
,LATERAL FLATTEN(input=>tab.DATA) s;

Output：

第2步：Pivot

WITH cte AS (
    SELECT id, s.VALUE:key::TEXT AS key, s.VALUE:value::TEXT AS value
    FROM tab
    ,LATERAL FLATTEN(input=>tab.DATA) s
)
SELECT *
FROM cte
PIVOT(MAX(value) FOR KEY IN ('Apple', 'Orange', 'Cookie')) AS p;

Output：