在Oracle数据库中,regexp_substr函数是一个非常强大的工具,它允许我们根据正则表达式模式从字符串中提取子字符串。以下是对你问题的详细回答: 解释regexp_substr函数在Oracle中的用途: regexp_substr函数主要用于从字符串中提取满足指定正则表达式模式的子字符串。它可以在复杂的字符串处理任务中发挥重要作用,比如数据清...
需要返回多行,可以采用oracle的connect by 命令,行数的获得通过length来获得。 select regexp_substr(‘2001,2002,200103,2005’, ‘[^,]+’, 1, level, ‘i’) as str from dual connect by level <= length(‘2001,2002,200103,2005’) - length(regexp_replace(‘2001,2002,200103,2005’, ‘,’,...
2)在oracle中rownum和level都是自动生成数字序列集合,结合connect by使用 selectDISTINCT regexp_substr('A,B,C,D,E,F','[^,]+',1,level)fromDUAL connect by level<= length('A,B,C,D,E,F') - length(replace('A,B,C,D,E,F',',','')) +1;selectDISTINCT regexp_substr('A,B,C,D,E,...
SELECT REGEXP_SUBSTR('文本123文本456文本789', '\d+') AS ID FROM DUAL; 这将返回结果为: ID 123 如果要提取多个ID号,可以使用循环或递归来实现。例如: WITH data AS ( SELECT '文本123文本456文本789' AS str FROM DUAL ) SELECT REGEXP_SUBSTR(str, '\d+', 1, LEVEL) AS ID FROM data...
REGEXP_SUBSTR 结合 CONECT BY LEVEL 代码语言:sql AI代码解释 SELECTregexp_substr(temp.STUDENT,'[^,]+',1,level)STUDENTFROM(SELECT'Student001,Student002,Student003'STUDENTFROMdual)tempCONNECTBYlevel<=REGEXP_COUNT('Student001,Student002,Student003','[^,]+');--Student001--Student002--Student003...
LEVEL --- 1 2 3 4 5 6 7 4、将上面REGEXP_SUBSTR的occurrence关联 [sql] SELECT NVL(REGEXP_SUBSTR('17,20,23', '[^,]+', 1, LEVEL, 'i'), 'NULLL') AS STR FROM DUAL CONNECT BY LEVEL <= 7; STR www.2cto.com --- 17 ...
SELECT REGEXP_SUBSTR('17,20,23','[^,]+',1,3,'i') AS STR FROM DUAL; 结果: STR --- 23 3、获取一个多个数值的列,从而能够让结果以多行的形式展示出来 [sql] SELECT LEVEL FROM DUAL CONNECT BY LEVEL <=7; 结果: LEVEL --- 1 ...
Oracle中的regexp_substr函数可以用于提取字符串中符合指定模式的子串,常用于复杂查询中对字符串的处理。以下是regexp_substr函数在复杂查询中的使用技巧:1. 提取字符串中...
The Oracle REGEXP_SUBSTR() function is an advanced version of the SUBSTR()function that allows you to search for substrings based on a regular expression. Instead of returning the position of the substring, it returns a portion of the source string that matches the regular expression. Syntax ...
select REGEXP_COUNT('GEORGE','GE',1,'i') from DUAL; 1、取分割后的所有结果 ( level oracle关键字,表示查询深度,用来实现层级查询) SELECT REGEXP_SUBSTR('a,b,c', '[^,]+', 1, LEVEL) AS COL FROM DUAL CONNECT BY LEVEL <= REGEXP_COUNT('a,b,c' , ',') + 1 ...