Sql 如何在大查询中正确卸载此数组?
我正在尝试创建一个如下表:Sql 如何在大查询中正确卸载此数组?,sql,google-bigquery,Sql,Google Bigquery,我正在尝试创建一个如下表: | year | week_number | first_week_day | last_week_day | ------------------------------------------------------- | 2019 | 1 | 2019-01-01 | 2019-01-07 | ....................................................... 我已经找到了一些方法,
| year | week_number | first_week_day | last_week_day |
-------------------------------------------------------
| 2019 | 1 | 2019-01-01 | 2019-01-07 |
.......................................................
我已经找到了一些方法,并决定使用EXTRACT和GENERATE_DATE。如果有更好的办法,请告诉我
以下是我到目前为止的情况:
#StandardSQL
WITH
dates_2018 AS
(SELECT GENERATE_DATE_ARRAY("2018-01-01", "2018-12-31") AS d_2018)
,dates_2019 AS
(SELECT GENERATE_DATE_ARRAY("2019-01-01", "2019-12-31") AS d_2019)
SELECT un
FROM dates_2018, UNNEST(d_2018) AS un
-- ,timestamps_2018 AS
-- (SELECT TIMESTAMP(dates_2018) AS timestamps_2018
-- FROM UNNEST(dates_2018))
-- ,d_2018 AS
-- (SELECT EXTRACT(year from timestamps_2018) AS year
-- ,EXTRACT(week from timestamps_2018) AS week
-- ,EXTRACT(day from timestamps_2018) AS day
-- FROM timestamps_2018)
-- SELECT *
-- FROM timestamps_2018
我现在的问题在于,我无法更正数组d_2018的UNNEST,因此我可以将所有元素转换为时间戳,以便稍后从中提取内容
当我取消测试时,它只返回第一行
主要是我在寻找这个令人不安的解决方案,但如果有人能提供更多建议,我会欢迎的。我不知道你为什么每年都要对数据进行分解。根据您的描述:
WITH dates AS (
SELECT GENERATE_DATE_ARRAY('2018-01-01', '2019-12-31') as date_array
)
select extract(year from d) as year, d,
EXTRACT(week from d) as week,
date_trunc(d, week) as first_week_day,
date_add(date_trunc(d, week), interval 6 day) as last_week_day
from dates cross join
unnest(date_array) d
ORDER BY d;
unest
将数组项转换为表行,以便可以对其运行SQL。
我不知道你想做什么,但你完全可以做类似的事情
选择
D
摘录(从d开始的一周)CW,
摘录(d日起)日,
摘录(从d开始的年份)年份
从UNNEST开始(生成日期数组(“2018-01-01”、“2019-12-31”)作为d
您将来自
generate\u date\u array()
#standardSQL
SELECT DISTINCT
EXTRACT(YEAR FROM day) AS year,
EXTRACT(WEEK FROM day) + 1 AS week_number,
DATE_TRUNC(day, WEEK) AS first_week_day,
DATE_ADD(DATE_TRUNC(day, week), INTERVAL 6 DAY) AS last_week_day
FROM UNNEST(GENERATE_DATE_ARRAY('2018-01-01', '2019-12-31')) AS day
我这样做是为了先测试2018年,然后测试其余时间。但是你在这里做了一些很好的魔术,我将不得不学习。不管怎样,它工作得很好,所以谢谢你!