数据提取Redshift正则表达式

Question

我正在尝试在下面的代码中寻找 * 后跟 SLD 的模式..

SELECT CASE WHEN REGEXP_COUNT(orderstatus,'^\*SLD') <> 0 
                 THEN TO_DATE(REGEXP_SUBSTR(orderstatus, '[0-9]{1,2}/[0-9]{1,2}') || '/2022', 'MM/DD/YYYY')
                 ELSE orddate
       END AS soldorstockdate
  FROM DATA;

但是我收到以下错误

数据库报告语法错误：重复运算符之前的正则表达式无效。解析正则表达式时发生错误：'^*>>>HERE>>>SLD'。详情：--------------------------------------------错误: 前面的正则表达式无效表格和数据的 DDL 如下

Create table input
(orderstatus varchar(100),
orddate date)

insert into input values
('*SLD 05/11/2022','5/1/2022'),
('*SOLD 05/15/2022','5/8/2022'),
('37141 SLD BAM','5/5/2022'),
('*STOCK 05/16/2022','5/3/2022'),
('1277489 STK#39298.32831','5/4/2022')

create table output
(orderstatus varchar(100),
orddate date
soldorstockdate date) 

insert into output values
('*SLD 05/11/2022','5/1/2022','5/11/2022'),
('*SOLD 05/15/2022','5/8/2022','5/15/2022'),
('37141 SLD BAM','5/5/2022','5/5/2022'),
('*STOCK 05/16/2022','5/3/2022','5/16/2022'),
('1277489 STK#39298.32831','5/4/2022','5/4/2022')

orderstatus	orddate	Soldorstockdate
*SLD 05/11/2022	5/1/2022	5/11/2022
*SOLD 05/15/2022	5/8/2022	5/15/2022
37141 SLD BAM	5/5/2022	5/5/2022
*STOCK 05/16/2022	5/3/2022	5/16/2022
1277489 STK#39298.32831	5/4/2022	5/4/2022

Answer 1

您必须使用双反斜杠 \ 而不是单反斜杠 \ 来转义元字符红移有 POSIX styled escape characters

To search for strings that include metacharacters, such as ‘. * | ? ‘, and so on, escape the character using two backslashes (' \ ').

SELECT *
     , REGEXP_COUNT(orderstatus, '^\*SLD') <> 0 -- Used \ here
     , CASE
           WHEN REGEXP_COUNT(orderstatus, '^\*SLD') <> 0 -- Used \ here
               THEN TO_DATE(REGEXP_SUBSTR(orderstatus, '[0-9]{1,2}/[0-9]{1,2}') || '/2022', 'MM/DD/YYYY')
           ELSE orddate
    END AS soldorstockdate
FROM input;

orderstatus	orddate	flag	soldorstockdate
*SLD 05/11/2022	2022-05-01	true	2022-05-11
*SOLD 05/15/2022	2022-05-08	false	2022-05-08
37141 SLD BAM	2022-05-05	false	2022-05-05
*STOCK 05/16/2022	2022-05-03	false	2022-05-03
1277489 STK#39298.32831	2022-05-04	false	2022-05-04

数据提取Redshift正则表达式

Data extraction Redshift regular expression

regex

sql

amazon-redshift