我的数据如下所示:
第 1 行 - {"id": "1", "object": "user","metadata": {"name": "1234"}}
第 2 行 - {"id": "1", "object": "user","metadata": {"name": "1234","email": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="7b1a19183b1a191855181416" rel="noreferrer noopener nofollow">[email protected]</a>"}}
我使用第 1 行创建了表格
metadata RECORD NULLABLE
metadata.tenant STRING NULLABLE
object STRING NULLABLE
id STRING NULLABLE
但是我的插入将在第 2 行失败。我的架构应该是什么样子才能处理元数据字段中的更改？
最佳答案
对于您的问题中显示的示例 - 我会使用以下架构
[
{
"name": "id",
"type": "INTEGER",
"mode": "NULLABLE"
},
{
"name": "object",
"type": "STRING",
"mode": "NULLABLE"
},
{
"name": "metadata",
"type": "STRING",
"mode": "NULLABLE"
}
]
下面是我如何处理它的示例
#standardSQL
WITH `yourProject.yourDataset.yourTable` AS (
SELECT 1 AS id, 'user' AS object, '{"name": "BI Architect", "email": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="bbdad9d8fbdad9d895d8d4d6" rel="noreferrer noopener nofollow">[email protected]</a>"}' AS metadata UNION ALL
SELECT 2, 'expert', '{"name": "Elliott Brossard"}'
)
SELECT
id,
object,
JSON_EXTRACT_SCALAR(metadata, '$.name') AS name,
JSON_EXTRACT_SCALAR(metadata, '$.email') AS email
FROM `yourProject.yourDataset.yourTable`
ORDER BY id
产生以下输出
id object name email
1 user BI Architect <a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="08696a6b48696a6b266b6765" rel="noreferrer noopener nofollow">[email protected]</a>
2 expert Elliott Brossard null
关于google-bigquery - 如何处理bigquery中的动态模式，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45178304/