BigQuery選擇多個鍵值

Question

通過將Firebase中的自定義事件導出到BigQuery，可以在其中存在多個鍵值參數。我似乎無法弄清楚如何使用「標準SQL」選擇其中的一種以上。

Answer 1

比方說，你想選擇與firebase_event_origin對應的string_value與firebase_screen_id所有control_reading事件相關的int_value。您可以將查詢表示爲：

#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';