从 Date 中获取周开始日期和周结束日期

Question

我需要从给定日期获取周开始日期和周结束日期，考虑到一周从星期日开始到星期六结束。

我提到了这篇文章，但这需要星期一作为一周的开始日。spark中是否有任何内置功能可以解决这个问题？

Answer 1

找出星期几并使用selectExpr遍历列，并将星期日作为星期开始日期

from pyspark.sql import functions as F


df_b = spark.createDataFrame([('1','2020-07-13')],[ "ID","date"])
df_b = df_b.withColumn('day_of_week', F.dayofweek(F.col('date')))
df_b = df_b.selectExpr('*', 'date_sub(date, day_of_week-1) as week_start')
df_b = df_b.selectExpr('*', 'date_add(date, 7-day_of_week) as week_end')

df_b.show()

+---+----------+-----------+----------+----------+
| ID|      date|day_of_week|week_start|  week_end|
+---+----------+-----------+----------+----------+
|  1|2020-07-13|          2|2020-07-12|2020-07-18|
+---+----------+-----------+----------+----------+

Spark SQL 中的更新

首先从数据框中创建一个临时视图

df_a.createOrReplaceTempView("df_a_sql")

代码在这里

%sql
select *, date_sub(date,dayofweek-1) as week_start,
date_sub(date, 7-dayofweek) as week_end
from
(select *, dayofweek(date) as dayofweek
from df_a_sql) T

输出

+---+----------+-----------+----------+----------+
| ID|      date|day_of_week|week_start|  week_end|
+---+----------+-----------+----------+----------+
|  1|2020-07-13|          2|2020-07-12|2020-07-18|
+---+----------+-----------+----------+----------+