如何使用 BigQuery API 从 TableResult 获取 json 格式的查询结果

我正在按照中给出的示例进行操作https://cloud.google.com/bigquery/create-simple-app-api#bigquery-simple-app-java https://cloud.google.com/bigquery/create-simple-app-api#bigquery-simple-app-java从 BigQuery API 获取查询结果。

TableResult result = queryJob.getQueryResults();

它以 TableResults 类型返回结果，但我需要以 json 格式获取结果。

TableResult{rows=[[FieldValue{attribute=PRIMITIVE, value=(...)},
    FieldValue{attribute=PRIMITIVE, value=(...)},
    FieldValue{attribute=PRIMITIVE, value=(...)},
    FieldValue{attribute=PRIMITIVE, value=(...)},
    FieldValue{attribute=PRIMITIVE, value=(...)},
    FieldValue{attribute=PRIMITIVE, value=(...)},
    FieldValue{attribute=PRIMITIVE, value=(...)}],(...)

如何将 TableResults 类型的结果转换为 json，甚至 csv？

要将表中的行转换为 JSON，您可以使用该函数TO_JSON_STRING [1] http://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#to_json_string。 要获取带格式的 JSON，您需要将参数“true”传递给函数。

新的查询将如下所示：

#standardSQL
“SELECT TO_JSON_STRING(t,true)"
 + "FROM ( 
    SELECT CONCAT('https://stackoverflow.com/questions/', CAST(id as STRING)) as url, "
     + "view_count "
     + "FROM `bigquery-public-data.stackoverflow.posts_questions` "
     + "WHERE tags like '%google-bigquery%' "
     + "ORDER BY favorite_count DESC LIMIT 10) as t”

Output:

TableResult{rows=[[FieldValue{attribute=PRIMITIVE, value={
  "url": "https://stackoverflow.com/questions/6607552",
  "view_count": 24524
}}], [FieldValue{attribute=PRIMITIVE, value={
  "url": "https://stackoverflow.com/questions/20349189",
  "view_count": 4298
}}], [FieldValue{attribute=PRIMITIVE, value={
  "url": "https://stackoverflow.com/questions/22734777",
  "view_count": 7940
}}], [FieldValue{attribute=PRIMITIVE, value={
  "url": "https://stackoverflow.com/questions/27537720",
  "view_count": 2039
(...)