BigQuery选择多个键值

Question

将Firebase中的自定义事件导出到BigQuery，其中可以存在多个键值参数。我似乎不知道如何使用＆＃34;标准SQL＆＃34;来选择其中一个以上。

Answer 1

我们假设您要为所有string_value事件选择与firebase_event_origin对应的int_value和与firebase_screen_id相关联的control_reading 。您可以将查询表达为：

#standardSQL
SELECT
  (SELECT param.value.string_value
   FROM UNNEST(event_dim.params) AS param
   WHERE param.key = 'firebase_event_origin') AS firebase_event_origin,
  (SELECT param.value.int_value
   FROM UNNEST(event_dim.params) AS param
   WHERE param.key = 'firebase_screen_id') AS firebase_screen_id
FROM `your_dataset.your_table_*`
CROSS JOIN UNNEST(event_dim) AS event_dim
WHERE _TABLE_SUFFIX BETWEEN '20170501' AND '20170503' AND
  event_dim.name = 'control_reading';