BigQuery Standart SQL：从时间戳中提取星期几名称

Question

我正在使用 BigQuery 标准 SQL。

我需要将时间戳转换为星期名称。

例如将今天的时间戳（2016-11-24 00:00:00）转换成字符串：'Thursday'

谢谢:)

Answer 1

您必须使用 DAYOFWEEK()，然后使用 CASE 语句 return 星期几。 DAYOFWEEK() returns 星期几作为 1（星期日）和 7（星期六）之间的整数。 Date and time functions

例如

SELECT 
  CASE 
    WHEN DAYOFWEEK(CURRENT_DATE()) = 1 THEN 'Sunday'
    WHEN DAYOFWEEK(CURRENT_DATE()) = 2 THEN 'Monday'
    WHEN DAYOFWEEK(CURRENT_DATE()) = 3 THEN 'Tuesday'
    WHEN DAYOFWEEK(CURRENT_DATE()) = 4 THEN 'Wednesday'
    WHEN DAYOFWEEK(CURRENT_DATE()) = 5 THEN 'Thursday'
    WHEN DAYOFWEEK(CURRENT_DATE()) = 6 THEN 'Friday'
    WHEN DAYOFWEEK(CURRENT_DATE()) = 7 THEN 'Saturday'
  END Weekday

Answer 2

以下适用于 BigQuery 标准 SQL

#standardSQL
SELECT 
  CURRENT_DATE() AS day,
  FORMAT_DATE('%a', CURRENT_DATE()) AS weekday_name_abbreviated,
  FORMAT_DATE('%A', CURRENT_DATE()) AS weekday_name_full

或

#standardSQL
SELECT 
  DATE('2016-11-24 00:00:00') AS day,
  FORMAT_DATE('%a', DATE('2016-11-24 00:00:00')) AS weekday_name_abbreviated,
  FORMAT_DATE('%A', DATE('2016-11-24 00:00:00')) AS weekday_name_full

结果是

day         weekday_name_abbreviated    weekday_name_full    
2016-11-24  Thu                         Thursday

Answer 3

在 BigQuery 中您可以使用：

SELECT

EXTRACT(DAYOFWEEK
  FROM
    {your_timestamp}) AS dayofweek,

FROM TABLE

它returns一个整数：1=星期一，7=星期日

BigQuery Standart SQL：从时间戳中提取星期几名称

BigQuery Standart SQL: extract day-of-week name from timestamp

sql

timestamp

google-bigquery

dayofweek