timestamp - 标准 SQL：无法从时间戳中提取 DAY

Question

我无法使用函数从名为repository.created_at的时间戳变量中提取天数。EXTRACT()

#standardSQL
SELECT repository.created_at AS fechas,
       EXTRACT(DAY FROM DATE repository.created_at)
FROM `bigquery-public-data.samples.github_nested`
LIMIT 100

怎么解决？

Answer 1

#standardSQL
SELECT 
  repository.created_at AS fechas,
  EXTRACT(DAY FROM PARSE_TIMESTAMP('%Y/%m/%d %X %z', repository.created_at))
FROM `bigquery-public-data.samples.github_nested`
LIMIT 100

Answer 2

该字段repository.created_at的类型为 STRING。您需要在提取日期之前将其解析为日期。

这应该有效：

SELECT repository.created_at AS fechas,
       EXTRACT(DAY FROM PARSE_DATE("%Y/%m/%d", 
SUBSTR(repository.created_at, 0, 10)))
FROM `bigquery-public-data.samples.github_nested`
LIMIT 100