使用google-cloud-python从BigQuery获取JSON格式的结果

Question

我通过google-cloud-python查询BigQuery，如下所示：

client = bigquery.Client()

query = """SELECT * FROM `{dataset}.{table}`
  WHERE id=@id LIMIT 1""".format(dataset=dataset,
                                 table=table)

param = ScalarQueryParameter('id', 'STRING', id)
query = client.run_sync_query(query, query_parameters=[param])
query.use_legacy_sql = False
query.timeout_ms = 1000
query.run()

assert query.complete

try:
    results = query.rows[0]
except IndexError:
    results = None

这将返回如下数据：

[
    "Tue, 11 Apr 2017 03:18:52 GMT",
    "A132",
    "United Kingdom",
    [
        {
            "endDate": "2012-12-05",
            "startDate": "2011-12-27",
            "statusCode": "Terminated"
        }
    ]
]

重复字段已转换为JSON。但我也希望将其余数据转换为JSON。我可以通过检查query.schema来实现它，但它似乎应该在库中，因为它已经在重复的元素中发生了。

如何使用这个库获得格式化为JSON的BigQuery查询结果？例如：

{
    "timestamp": "Tue, 11 Apr 2017 03:18:52 GMT",
    "id": "A132",
    "country": "United Kingdom",
    [
        {
            "endDate": "2012-12-05",
            "startDate": "2011-12-27",
            "statusCode": "Terminated"
        }
    ]
}

Answer 1

事实证明，代码非常简单：

field_names = [f.name for f in query.schema]

try:
    raw_results = query.rows[0]
    zipped_results = zip(field_names, raw_results)
    results = {x[0]: x[1] for x in zipped_results}
except IndexError:
    results = None