使用 Hive 或 sql 进行日期转换

Posted 2023-03-23

【中文标题】使用 Hive 或 sql 进行日期转换

【英文标题】：Date Transformation using Hive or sql

【发布时间】：2020-04-09 01:56:33

【问题描述】：

前提：您有一个表，其中包含一列 original_date，数据类型为字符串：

ORIGINAL_DATE  
20190825 
20190826 
20190827 
20190828 
20190829 
20190830 
20190831 
20190901 

问题：编写一个 SQL 查询来计算另外两列 - end_of_week - 来自 original_date 的下周日的日期。如果original_date 已经是星期天，则该字段应该是相同的值end_of_month - 月末日期的值 可接受的解决方案是适用于original_date 字符串格式的任何有效日期。计算 end_of_month 和 end_of_week

ORIGINAL_DATE    END_OF_WEEK     END_OF_MONTH  
20190825    20190825    20190831 
20190826    20190901    20190831 
20190827    20190901    20190831 
20190828    20190901    20190831 
20190829    20190901    20190831 
20190830    20190901    20190831 
20190831    20190901    20190831 
20190901    20190901    20190930 

附加信息：

20190825 是星期日，因此该值的 end_of_week 仍然是同一日期。

20190827 是星期二，下个星期日是 20190901

CREATE TABLE random_dates ( original_date VARCHAR(8) NOT NULL  ); 

INSERT INTO random_dates(original_date) values('20190825'); 
INSERT INTO random_dates(original_date) values('20190826'); 
INSERT INTO random_dates(original_date) values('20190827'); 
INSERT INTO random_dates(original_date) values('20190828'); 
INSERT INTO random_dates(original_date) values('20190829'); 
INSERT INTO random_dates(original_date) values('20190830'); 
INSERT INTO random_dates(original_date) values('20190831'); 
INSERT INTO random_dates(original_date) values('20190901');

预期输出：

20190825    2019-08-25  2019-08-31 
 20190826   2019-09-01  2019-08-31 
 20190827   2019-09-01  2019-08-31 
 20190828   2019-09-01  2019-08-31 
 20190829   2019-09-01  2019-08-31 
 20190830   2019-09-01  2019-08-31 
 20190831   2019-09-01  2019-08-31
 20190901   2019-09-01  2019-09-30

【参考方案1】：

Hive 解决方案：

with random_dates as (--this is your example dataset
select stack(8,
'20190825', '20190826', '20190827', '20190828', '20190829', '20190830', '20190831', '20190901'
) as original_date
)

select original_date,
       date_add(date_formatted, 6-days)  end_of_week,
       last_day(date_formatted)          end_of_month
  from       
      (
       select original_date, 
              regexp_replace(original_date,'^(\\d4)(\\d2)(\\d2)$','$1-$2-$3') date_formatted,
              pmod(datediff(regexp_replace(original_date,'^(\\d4)(\\d2)(\\d2)$','$1-$2-$3'),'1900-01-08'),7) days
         from random_dates
      )s
;

结果：

original_date   end_of_week end_of_month
20190825    2019-08-25  2019-08-31
20190826    2019-09-01  2019-08-31
20190827    2019-09-01  2019-08-31
20190828    2019-09-01  2019-08-31
20190829    2019-09-01  2019-08-31
20190830    2019-09-01  2019-08-31
20190831    2019-09-01  2019-08-31
20190901    2019-09-01  2019-09-30

【参考方案2】：

SELECT original_date,
CASE  DAYOFWEEK(STR_TO_DATE(original_date,'%Y%m%d'))
WHEN 1 THEN  DATE_ADD(STR_TO_DATE(original_date,'%Y%m%d'),INTERVAL 0 DAY)
WHEN 2 THEN  DATE_ADD(STR_TO_DATE(original_date,'%Y%m%d'),INTERVAL 6 DAY)
WHEN 3 THEN  DATE_ADD(STR_TO_DATE(original_date,'%Y%m%d'),INTERVAL 5 DAY)
WHEN 4 THEN  DATE_ADD(STR_TO_DATE(original_date,'%Y%m%d'),INTERVAL 4 DAY)
WHEN 5 THEN  DATE_ADD(STR_TO_DATE(original_date,'%Y%m%d'),INTERVAL 3 DAY)
WHEN 6 THEN  DATE_ADD(STR_TO_DATE(original_date,'%Y%m%d'),INTERVAL 2 DAY)
WHEN 7 THEN  DATE_ADD(STR_TO_DATE(original_date,'%Y%m%d'),INTERVAL 1 DAY)
END AS END_OF_WEEK,
LAST_DAY(STR_TO_DATE(original_date,'%Y%m%d')) AS END_OF_MONTH
FROM random_dates;

【讨论】：

您能提供一些背景信息吗？你的代码 sn-p 在做什么（为什么）？ :)