SQL：从嵌套对象中提取 JSON答案

【问题标题】：SQL: JSON Extract from nested objectSQL：从嵌套对象中提取 JSON
【发布时间】：2021-06-10 23:53:37
【问题描述】：

我有一张这样的桌子

id	obj
1	{"is_from_shopping_bag":true,"products":[{"price":{"amount":"18.00","currency":"USD","offset":100,"amount_with_offset":"1800"},"product_id":"1234","quantity":1}],"source":"cart"}
2	{"is_from_shopping_bag":false,"products":[{"price":{"amount":"80.00","currency":"USD","offset":100,"amount_with_offset":"8000"},"product_id":"2345","quantity":1}],"source":"pdp"}

我正在 Hive 中执行 sql 查询以获取“货币”字段。

目前我可以运行

SELECT
    JSON_EXTRACT( obj, '$.products')
FROM my_table

obj
[{"price":{"amount":"18.00","currency":"USD","offset":100,"amount_with_offset":"1800"},"product_id":"1234","quantity":1}]
[{"price":{"amount":"80.00","currency":"USD","offset":100,"amount_with_offset":"8000"},"product_id":"2345","quantity":1}]

如何更深入地获得货币？

【问题讨论】：

标签： sql hive

【解决方案1】：

获取第一个产品使用的货币：

SELECT
    id,JSON_EXTRACT( obj, '$.products[0].price.currency') first_product_currency
FROM my_table;

id	first_product_currency
1	"USD"
2	"USD"

获取所有产品使用的货币：

SELECT
    id,JSON_EXTRACT( obj, '$.products[*].price.currency') multiple_currencies
FROM my_table;

id	multiple_currencies
1	["USD"]
2	["USD"]

【讨论】：