查询雪花中的半结构化字段

如何解决查询雪花中的半结构化字段

我在 SNowflake 中有一个表，它有一个 varchar 类型的字段，但其中的数据结构为 json（不理想，我知道）。鉴于此字段中的以下示例数据，我将如何在此字段的查询中同时返回“id”值和“tax_lines.price_set.amount”值？

例如

{
    "self": [{
        "id": "abcdefg","location": {
            "address1": "11234 street name"
        },"tax_lines": [{
            "price": 1.04,"price_set": {
                "presentment_money": {
                    "amount": "1.04","currency_code": "USD"
                },"shop_money": {
                    "amount": "1.04","currency_code": "USD"
                }
            },"rate": 0.0575,"title": "xx STATE TAX"
        },{
            "price": 0.18,"price_set": {
                "presentment_money": {
                    "amount": "0.18","shop_money": {
                    "amount": "0.18","rate": 0.01,"title": "XX COUNTY TAX"
        }]
    }]
}

非常感谢任何帮助！

解决方法

通过使用函数 JSON_EXTRACT_PATH_TEXT

select *,JSON_EXTRACT_PATH_TEXT(jsonColumn,'self[0].id') id,'self[0].tax_lines[0].price_set.presentment_money.amount') amount1
from table

,

您需要使用 VARIANT 数据类型和 LATERAL FLATTEN 在 Snowflake 中处理此类数据。

select var:self[0]:id::string,value:price_set:presentment_money:amount::float,value:price_set:shop_money:amount::float
from json_table,lateral flatten(input => var:self[0]:tax_lines);

会给你以下结果：

ID         PRESENTMENT_AMOUNT SHOP_MONEY_AMOUNT
abcdefg    1.04               1.04
abcdefg    0.18               0.18

这是完整的工作簿：

create database stackoverflow;

use database stackoverflow;

create or replace table json_table (var variant);

insert into json_table (var)
  select  parse_json('{
    "self": [{
        "id": "abcdefg","location": {
            "address1": "11234 street name"
        },"tax_lines": [{
            "price": 1.04,"price_set": {
                "presentment_money": {
                    "amount": "1.04","currency_code": "USD"
                },"shop_money": {
                    "amount": "1.04","currency_code": "USD"
                }
            },"rate": 0.0575,"title": "xx STATE TAX"
        },{
            "price": 0.18,"price_set": {
                "presentment_money": {
                    "amount": "0.18","shop_money": {
                    "amount": "0.18","rate": 0.01,"title": "XX COUNTY TAX"
        }]
    }]
}');

select var:self[0]:id::string,lateral flatten(input => var:self[0]:tax_lines);