尝试使用BigQuery选择事件数据时出错

Question

我正在尝试event_dim.date在BigQuery中选择但由于错误而无法实际访问它

Error: Cannot access field date on a value with type ARRAY<STRUCT<date STRING, name STRING, params ARRAY<STRUCT<key STRING, value STRUCT<string_value STRING, int_value INT64, float_value FLOAT, ...>>>, ...>> at [1:18]

我的查询:

SELECT event_dim.date FROM `table`

我知道我做错了什么,非常感谢任何帮助.谢谢!

Answer 1

您是否想要获取每行的日期数组？然后你想要一个ARRAY子查询:

SELECT ARRAY(SELECT date FROM UNNEST(event_dim)) AS dates
FROM `table`;

如果您尝试将所有日期分别放在单独的行中,那么您希望与数组交叉连接:

SELECT event.date
FROM `table`
CROSS JOIN UNNEST(event_dim) AS event;

过滤特定日期:

SELECT event.date
FROM `table`
CROSS JOIN UNNEST(event_dim) AS event
WHERE event.date = '20170104';

或者,您可以将日期字符串解析为date类型,这样可以过滤年份或周,例如:

SELECT date
FROM (
  SELECT PARSE_DATE('%Y%m%d', event.date) AS date
  FROM `table`
  CROSS JOIN UNNEST(event_dim) AS event
)
WHERE EXTRACT(YEAR FROM date) = 2017;