上周日在 Vertica SQL？

Question

检查过 vsql 没有 dateadd 函数。

来自 pandas datetime.dt(year=x, week=y...)

有什么方法可以在此处输入自定义日期以实现以下目标

GETDATE()+datediff(day=1, week=WEEK_ISO(GETDATE()) - 1)

Answer 1

我刚刚准备了一个测试程序，我根据 ISO 和标准计算一周的第一天，以及一个月的第一天，还有 ISO 和“标准”的最后一天" 一系列日期的一周。

这是完整的脚本及其结果——它还展示了如何使用 TIMESERIES 从无到有地创建日期列表：

WITH dtlimits(dt) AS (
            SELECT DATE '2021-12-20'
  UNION ALL SELECT DATE '2022-01-10'
)
,
dtlist AS (
  SELECT
    tsd::DATE AS dt
  FROM dtlimits
  TIMESERIES tsd AS '1 DAY' OVER(ORDER BY dt::TIMESTAMP)
)
SELECT
  dt
, TO_CHAR(dt,'Dy') AS wkday
, dayofweek(dt)
, dayofweek_iso(dt)
, YEAR(dt)*100+WEEK(dt) AS yw
, YEAR(dt)*100+WEEK_ISO(dt)  AS ywiso
, (dt - dayofweek_iso(dt) + 1)                         AS firstdowiso
, (dt - dayofweek(dt) + 1    )                         AS firstdow
, ((dt - dayofweek(dt) + 6    ) + (86399/86400))::DATE AS lastdow
, ((dt - dayofweek_iso(dt) + 6) + (86399/86400))::DATE AS lastdowiso
, dayofmonth(dt)             AS dom
FROM dtlist;
-- out      dt     | wkday | dayofweek | dayofweek_iso |   yw   | ywiso  | firstdowiso |  firstdow  |  lastdow   | lastdowiso | dom 
-- out ------------+-------+-----------+---------------+--------+--------+-------------+------------+------------+------------+-----
-- out  2021-12-20 | Mon   |         2 |             1 | 202152 | 202151 | 2021-12-20  | 2021-12-19 | 2021-12-24 | 2021-12-25 |  20
-- out  2021-12-21 | Tue   |         3 |             2 | 202152 | 202151 | 2021-12-20  | 2021-12-19 | 2021-12-24 | 2021-12-25 |  21
-- out  2021-12-22 | Wed   |         4 |             3 | 202152 | 202151 | 2021-12-20  | 2021-12-19 | 2021-12-24 | 2021-12-25 |  22
-- out  2021-12-23 | Thu   |         5 |             4 | 202152 | 202151 | 2021-12-20  | 2021-12-19 | 2021-12-24 | 2021-12-25 |  23
-- out  2021-12-24 | Fri   |         6 |             5 | 202152 | 202151 | 2021-12-20  | 2021-12-19 | 2021-12-24 | 2021-12-25 |  24
-- out  2021-12-25 | Sat   |         7 |             6 | 202152 | 202151 | 2021-12-20  | 2021-12-19 | 2021-12-24 | 2021-12-25 |  25
-- out  2021-12-26 | Sun   |         1 |             7 | 202153 | 202151 | 2021-12-20  | 2021-12-26 | 2021-12-31 | 2021-12-25 |  26
-- out  2021-12-27 | Mon   |         2 |             1 | 202153 | 202152 | 2021-12-27  | 2021-12-26 | 2021-12-31 | 2022-01-01 |  27
-- out  2021-12-28 | Tue   |         3 |             2 | 202153 | 202152 | 2021-12-27  | 2021-12-26 | 2021-12-31 | 2022-01-01 |  28
-- out  2021-12-29 | Wed   |         4 |             3 | 202153 | 202152 | 2021-12-27  | 2021-12-26 | 2021-12-31 | 2022-01-01 |  29
-- out  2021-12-30 | Thu   |         5 |             4 | 202153 | 202152 | 2021-12-27  | 2021-12-26 | 2021-12-31 | 2022-01-01 |  30
-- out  2021-12-31 | Fri   |         6 |             5 | 202153 | 202152 | 2021-12-27  | 2021-12-26 | 2021-12-31 | 2022-01-01 |  31
-- out  2022-01-01 | Sat   |         7 |             6 | 202201 | 202252 | 2021-12-27  | 2021-12-26 | 2021-12-31 | 2022-01-01 |   1
-- out  2022-01-02 | Sun   |         1 |             7 | 202202 | 202252 | 2021-12-27  | 2022-01-02 | 2022-01-07 | 2022-01-01 |   2
-- out  2022-01-03 | Mon   |         2 |             1 | 202202 | 202201 | 2022-01-03  | 2022-01-02 | 2022-01-07 | 2022-01-08 |   3
-- out  2022-01-04 | Tue   |         3 |             2 | 202202 | 202201 | 2022-01-03  | 2022-01-02 | 2022-01-07 | 2022-01-08 |   4
-- out  2022-01-05 | Wed   |         4 |             3 | 202202 | 202201 | 2022-01-03  | 2022-01-02 | 2022-01-07 | 2022-01-08 |   5
-- out  2022-01-06 | Thu   |         5 |             4 | 202202 | 202201 | 2022-01-03  | 2022-01-02 | 2022-01-07 | 2022-01-08 |   6
-- out  2022-01-07 | Fri   |         6 |             5 | 202202 | 202201 | 2022-01-03  | 2022-01-02 | 2022-01-07 | 2022-01-08 |   7
-- out  2022-01-08 | Sat   |         7 |             6 | 202202 | 202201 | 2022-01-03  | 2022-01-02 | 2022-01-07 | 2022-01-08 |   8
-- out  2022-01-09 | Sun   |         1 |             7 | 202203 | 202201 | 2022-01-03  | 2022-01-09 | 2022-01-14 | 2022-01-08 |   9
-- out  2022-01-10 | Mon   |         2 |             1 | 202203 | 202202 | 2022-01-10  | 2022-01-09 | 2022-01-14 | 2022-01-15 |  10

上周日在 Vertica SQL？

Last Sunday in Vertica SQL?

python

mysql

sql

date

vertica