Oracle 正则表达式（详细） |
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Oracle 正则表达式 目录一. 匹配字符二.重复字符三、定位字符四、分组字符4.1（） 捕获组4.2 （?:） 非捕获组4.3（?）捕获组命名4.4（?=） 正声明4.5 （?!）负声明4.6 （?它将实现如下匹配：56F 89C 4.8 （?>）非回溯组（?>） 非回溯组。防止Regex引擎回溯并且防止实现一次匹配 示例： 假设要匹配所有以“ing”结尾的单词。输入字符串如下：He was very trusing 正则表达式为：.*ing 它将实现一次匹配――单词trusting。“.”匹配任意字符，当然也匹配“ing”。所以，Regex引擎回溯一位并在第2个“t”停止，然后匹配指定的模式“ing”。但是，如果禁用回溯操作：(?>.*)ing 它将实现0次匹配。“.”能匹配所有的字符，包括“ing”――不能匹配，从而匹配失败 五、决策字符 5.1 正则表达式决策字符（?(regex)yes_regex|no_regex） 如果表达式regex匹配，那么将试图匹配表达式yes。否则匹配表达式no。正则表达式no是可先参数。注意，作出决策的模式宽度为0.这意味着表达式yes或no将从与regex表达式相同的位置开始匹配 示例： 正则表达式(?(\d)\dA|(A-Z)B)要匹配的输入字符串为：1A CB3A5C 3B 它实现的匹配是： 1A CB 3A 5.2 组决策字符（?(group name or number)yes_regex|no_regex） 如果组中的正则表达式实现了匹配，那么试图匹配yes正则表达式。否则，试图匹配正则表达式no。no是可先的参数 示例： 正则表达式(\d7)?-(?(1)\d\d[A-Z]|[A-Z][A-Z]要匹配的输入字符串为： 77-77A 69-AA 57-B 它实现的匹配为： 77-77A －AA 注：上面表中列出的字符强迫处理器执行一次if-else决策 六、替换字符 $group 用group指定的组号的值 ${name} 被一个(?)组匹配的最后子串的值 \[ 代表一个字符$ \] $^ 代表输入字符串匹配之前的所有文本 $’ 代表输入字符串匹配之后的所有文本 $+ 代表最后捕获的组 $_ 代表整个的输入字符串注：以上为常用替换字符，不全 七、转义序列\ 匹配字符“\” . 匹配字符“.” * 匹配字符“*” + 匹配字符“+” ? 匹配字符“?” | 匹配字符“|” ( 匹配字符“(” ) 匹配字符“)” { 匹配字符“{” } 匹配字符“}” ^ 匹配字符“^” $ 匹配字符“$” \n 匹配换行符 \r 匹配回车符 \t 匹配制表符 \v 匹配垂直制表符 \f 匹配换面符 \nnn 匹配一个8进数字，nnn指定的ASCII字符。如\103匹配大写的C \xnn 匹配一个16进数字，nn指定的ASCII字符。如\x43匹配大写的C \unnnn 匹配由4位16进数字（由nnnn表示）指定的Unicode字符 \cV 匹配一个控制字符，如\cV匹配Ctrl-V 八、选项标志 I IgnoreCase M Multiline N ExplicitCapture S SingleLine X IgnorePatternWhitespace注：选项本身的信作含义如下表所示： 标 志 名 称: IgnoreCase 使模式匹配不区分大小写。默认的选项是匹配区分大小写 RightToLeft 从右到左搜索输入字符串。默认是从左到右以符合英语等的阅读习惯，但不符合阿拉伯语或希伯来语的阅读习惯 None 不设置标志。这是默认选项 Multiline 指定^和$可以匹配行首和行尾，以及字符串的开始和结尾。这意味着可以匹配每个用换行符分隔的行。但是，字符“.”仍然不匹配换行符 SingleLine 规定特殊字符“.”匹配任意的字符，包括换行符。默认情况下，特殊字符“.”不匹配换行符。通常与MultiLine选项一起使用 ECMAScript. ECMA(European Coputer Manufacturer’s Association,欧洲计算机生产商协会)已经定义了正则表达式应该如何实现，而且已经在ECMAScript规范中实现，这是一个基于标准的JavaScript。这个选项只能与IgnoreCase和MultiLine标志一起使用。与其它任何标志一起使用，ECMAScript都将产生异常 IgnorePatternWhitespace 此选项从使用的正则表达式模式中删除所有非转义空白字符。它使表达式能跨越多行文本，但必须确保对模式中所有的空白进行转义。如果设置了此选项，还可以使用“#”字符来注释下则表达式 Complied 它把正则表达式编译为更接近机器代码的代码。这样速度快，但不允许对它进行任何修改 九、oracle的正则表达式(regular expression)简单介绍目前，正则表达式已经在很多软件中得到广泛的应用，包括*nix（Linux, Unix等），HP等操作系统，PHP，C#，Java等开发环境。 Oracle 10g正则表达式提高了SQL灵活性。有效的解决了数据有效性， 重复词的辨认, 无关的空白检测，或者分解多个正则组成 的字符串等问题。 Oracle 10g支持正则表达式的四个新函数分别是：REGEXP_LIKE、REGEXP_INSTR、REGEXP_SUBSTR、和REGEXP_REPLACE。 它们使用POSIX 正则表达式代替了老的百分号（%）和通配符（_）字符。 9.1 REGEXP_REPLACEREGEXP_REPLACE(source_string,pattern,replace_string,position,occurtence,match_parameter)函数(10g新函数) 描述:字符串替换函数。相当于增强的replace函数。Source_string指定源字符表达式；pattern指定规则表达式；replace_string指定用于替换的字符串；position指定起始搜索位置；occurtence指定替换出现的第n个字符串；match_parameter指定默认匹配操作的文本串。 其中replace_string,position,occurtence,match_parameter参数都是可选的。 9.2 REGEXP_SUBSTRREGEXP_SUBSTR(source_string, pattern[,position [, occurrence[, match_parameter]]])函数(10g新函数) 描述：返回匹配模式的子字符串。相当于增强的substr函数。Source_string指定源字符表达式；pattern指定规则表达式；position指定起始搜索位置；occurtence指定替换出现的第n个字符串；match_parameter指定默认匹配操作的文本串。 其中position,occurtence,match_parameter参数都是可选的match_option的取值如下： ‘c’ 说明在进行匹配时区分大小写（缺省值）； 'i' 说明在进行匹配时不区分大小写； 'n' 允许使用可以匹配任意字符的操作符； 'm' 将x作为一个包含多行的字符串。 9.3 REGEXP_LIKEREGEXP_LIKE(source_string, pattern[, match_parameter])函数(10g新函数) 描述：返回满足匹配模式的字符串。相当于增强的like函数。Source_string指定源字符表达式；pattern指定规则表达式；match_parameter指定默认匹配操作的文本串。 其中position,occurtence,match_parameter参数都是可选的 9.4 REGEXP_INSTRREGEXP_INSTR(source_string, pattern[, start_position[, occurrence[, return_option[, match_parameter]]]])函数(10g新函数) 描述: 该函数查找 pattern ，并返回该模式的第一个位置。您可以随意指定您想要开始搜索的 start_position。 occurrence 参数默认为 1，除非您指定您要查找接下来出现的一个模式。return_option 的默认值为 0，它返回该模式的起始位置；值为 1 则返回符合匹配条件的下一个字符的起始位置 9.5 特殊字符：'^' 匹配输入字符串的开始位置，在方括号表达式中使用，此时它表示不接受该字符集合。 '$' 匹配输入字符串的结尾位置。如果设置了 RegExp 对象的 Multiline 属性，则 $ 也匹配 'n' 或 'r'。 '.' 匹配除换行符 n之外的任何单字符。 '?' 匹配前面的子表达式零次或一次。 '*' 匹配前面的子表达式零次或多次。 '+' 匹配前面的子表达式一次或多次。 '( )' 标记一个子表达式的开始和结束位置。 '[]' 标记一个中括号表达式。 '{m,n}' 一个精确地出现次数范围，m= select * from test; ID MC -------------------- ------------------------------------------------------------ A AAAAA a aaaaa B BBBBB b bbbbb SQL> select * from test where regexp_like(id,'b','i'); --不区分数据大小写 ID MC -------------------- ------------------------------------------------------------ B BBBBB b bbbbb General Information Anchoring Characters Character Class Description ^ Anchor the expression to the start of a line $ Anchor the expression to the end of a line 十一、官方说明(英文原版说明) Equivalence Classes Character Class Description = = Oracle supports the equivalence classes through the POSIX '[==]' syntax. A base letter and all of its accented versions constitute an equivalence class. For example, the equivalence class '[=a=]' matches ?nd ?The equivalence classes are valid only inside the bracketed expression 11.1 Match Options Character Class Description c Case sensitive matching i Case insensitive matching m Treat source string as multi-line activating Anchor chars n Allow the period (.) to match any newline character 11.2 Posix Characters Character Class Description [:alnum:] Alphanumeric characters [:alpha:] Alphabetic characters [:blank:] Blank Space Characters [:cntrl:] Control characters (nonprinting) [:digit:] Numeric digits [:graph:] Any [:punct:], [:upper:], [:lower:], and [:digit:] chars [:lower:] Lowercase alphabetic characters [:print:] Printable characters [:punct:] Punctuation characters [:space:] Space characters (nonprinting), such as carriage return, newline, vertical tab, and form feed [:upper:] Uppercase alphabetic characters [:xdigit:] Hexidecimal characters 11.3 Quantifier Characters Character Class Description'*' Match 0 or more times '?' Match 0 or 1 time '+' Match 1 or more times {m} Match exactly m times {m,} Match at least m times {m, n} Match at least m times but no more than n times \n Cause the previous expression to be repeated n times 11.4 Alternative Matching And Grouping Characters Character Class Description| Separates alternates, often used with grouping operator () ( ) Groups subexpression into a unit for alternations, for quantifiers, or for backreferencing (see "Backreferences" section) [char] Indicates a character list; most metacharacters inside a character list are understood as literals, with the exception of character classes, and the ^ and - metacharacters 十二 英文示例Demo Table CREATE TABLE test ( testcol VARCHAR2(50)); INSERT INTO test VALUES ('abcde'); INSERT INTO test VALUES ('12345'); INSERT INTO test VALUES ('1a4A5'); INSERT INTO test VALUES ('12a45'); INSERT INTO test VALUES ('12aBC'); INSERT INTO test VALUES ('12abc'); INSERT INTO test VALUES ('12ab5'); INSERT INTO test VALUES ('12aa5'); INSERT INTO test VALUES ('12AB5'); INSERT INTO test VALUES ('ABCDE'); INSERT INTO test VALUES ('123-5'); INSERT INTO test VALUES ('12.45'); INSERT INTO test VALUES ('1a4b5'); INSERT INTO test VALUES ('1 3 5'); INSERT INTO test VALUES ('1 45'); INSERT INTO test VALUES ('1 5'); INSERT INTO test VALUES ('a b c d'); INSERT INTO test VALUES ('a b c d e'); INSERT INTO test VALUES ('a e'); INSERT INTO test VALUES ('Steven'); INSERT INTO test VALUES ('Stephen'); INSERT INTO test VALUES ('111.222.3333'); INSERT INTO test VALUES ('222.333.4444'); INSERT INTO test VALUES ('333.444.5555'); INSERT INTO test VALUES ('abcdefabcdefabcxyz'); COMMIT; 12.1 REGEXP_COUNTSyntax REGEXP_COUNT(, [[, ], []]) -- match parameter: 'c' = case sensitive 'i' = case insensitive search 'm' = treats the source string as multiple lines 'n' = allows the period (.) wild character to match newline 'x' = ignore whitespace charactersCount's occurrences based on a regular expression SELECT REGEXP_COUNT(testcol, '2a', 1, 'i') RESULT FROM test; SELECT REGEXP_COUNT(testcol, 'e', 1, 'i') RESULT FROM test; 12.2 REGEXP_INSTRSyntax REGEXP_INSTR(, [[, ][, ][, ][, ][, ]]) Find words beginning with 's' or 'r' or 'p' followed by any 4 alphabetic characters: case insensitive SELECT REGEXP_INSTR('500 Oracle Pkwy, Redwood Shores, CA', '[o][[:alpha:]]{3}', 1, 1, 0, 'i') RESULT FROM dual; SELECT REGEXP_INSTR('500 Oracle Pkwy, Redwood Shores, CA', '[o][[:alpha:]]{3}', 1, 1, 1, 'i') RESULT FROM dual; SELECT REGEXP_INSTR('500 Oracle Pkwy, Redwood Shores, CA', '[o][[:alpha:]]{3}', 1, 2, 0, 'i') RESULT FROM dual; SELECT REGEXP_INSTR('500 Oracle Pkwy, Redwood Shores, CA', '[o][[:alpha:]]{3}', 1, 2, 1, 'i') RESULT FROM dual; Find the position of try, trying, tried or tries SELECT REGEXP_INSTR('We are trying to make the subject easier.', 'tr(y(ing)?|(ied)|(ies))') RESULTNUM FROM dual; Using Sub-Expression option SELECT testcol, REGEXP_INSTR(testcol, 'ab', 1, 1, 0, 'i', 0) FROM test; SELECT testcol, REGEXP_INSTR(testcol, 'ab', 1, 1, 0, 'i', 1) FROM test; SELECT testcol, REGEXP_INSTR(testcol, 'a(b)', 1, 1, 0, 'i', 1) FROM test; 12.3 REGEXP_LIKESyntax REGEXP_LIKE(, , ) AlphaNumeric Characters SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:alnum:]]'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:alnum:]]{3}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:alnum:]]{5}'); Alphabetic Characters SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:alpha:]]'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:alpha:]]{3}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:alpha:]]{5}'); Control Characters INSERT INTO test VALUES ('zyx' || CHR(13) || 'wvu'); COMMIT; SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:cntrl:]]{1}');Digits SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:digit:]]'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:digit:]]{3}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:digit:]]{5}'); Lower Case SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:lower:]]'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:lower:]]{2}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:lower:]]{3}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:lower:]]{5}'); Printable Characters SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:print:]]{5}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:print:]]{6}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:print:]]{7}'); Punctuation TRUNCATE TABLE test; SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:punct:]]'); Spaces SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:space:]]'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:space:]]{2}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:space:]]{3}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:space:]]{5}'); Upper Case SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:upper:]]'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:upper:]]{2}'); SELECT * FROM test WHERE REGEXP_LIKE(testcol, '[[:upper:]]{3}'); Values Starting with 'a%b' SELECT testcol FROM test WHERE REGEXP_LIKE(testcol, '^ab*'); 'a' is the third value SELECT testcol FROM test WHERE REGEXP_LIKE(testcol, '^..a.'); Contains two consecutive occurances of the letter 'a' or 'z' SELECT testcol FROM test WHERE REGEXP_LIKE(testcol, '([az])\1', 'i'); Begins with 'Ste' ends with 'en' and contains either 'v' or 'ph' in the center SELECT testcol FROM test WHERE REGEXP_LIKE(testcol, '^Ste(v|ph)en$'); Use a regular expression in a check constraint CREATE TABLE mytest (c1 VARCHAR2(20), CHECK (REGEXP_LIKE(c1, '^[[:alpha:]]+$'))); Identify SSN CREATE TABLE ssn_test ( ssn_col VARCHAR2(20)); INSERT INTO ssn_test VALUES ('111-22-3333'); INSERT INTO ssn_test VALUES ('111=22-3333'); INSERT INTO ssn_test VALUES ('111-A2-3333'); INSERT INTO ssn_test VALUES ('111-22-33339'); INSERT INTO ssn_test VALUES ('111-2-23333'); INSERT INTO ssn_test VALUES ('987-65-4321'); COMMIT; SELECT ssn_col from ssn_test WHERE REGEXP_LIKE(ssn_col,'^[0-9]{3}-[0-9]{2}-[0-9]{4}$'); 12.4 REGEXP_REPLACESyntax REGEXP_REPLACE(, , , , , ) Looks for the pattern xxx.xxx.xxxx and reformats pattern to (xxx) xxx-xxxx col testcol format a15 col result format a15 SELECT testcol, REGEXP_REPLACE(testcol, '([[:digit:]]{3})\.([[:digit:]]{3})\.([[:digit:]]{4})', '(\1) \2-\3') RESULT FROM test WHERE LENGTH(testcol) = 12; Put a space after every character SELECT testcol, REGEXP_REPLACE(testcol, '(.)', '\1 ') RESULT FROM test WHERE testcol like 'S%'; Replace multiple spaces with a single space SELECT REGEXP_REPLACE('500 Oracle Parkway, Redwood Shores, CA', '( ){2,}', ' ') RESULT FROM dual; Insert a space between a lower case character followed by an upper case character SELECT REGEXP_REPLACE('George McGovern', '([[:lower:]])([[:upper:]])', '\1 \2') CITY FROM dual; Replace the period with a string (note use of '\') SELECT REGEXP_REPLACE('We are trying to make the subject easier.','\.',' for you.') REGEXT_SAMPLE FROM dual; Demo CREATE TABLE t( testcol VARCHAR2(10)); INSERT INTO t VALUES ('1'); INSERT INTO t VALUES ('2 '); INSERT INTO t VALUES ('3 new '); col newval format a10 SELECT LENGTH(testcol) len, testcol origval, REGEXP_REPLACE(testcol, '\W+$', ' ') newval, LENGTH(REGEXP_REPLACE(testcol, '\W+$', ' ')) newlen FROM t; 12.5 REGEXP_SUBSTRSyntax REGEXP_SUBSTR(source_string, pattern[, position [, occurrence[, match_parameter]]]) Searches for a comma followed by one or more occurrences of non-comma characters followed by a comma SELECT REGEXP_SUBSTR('500 Oracle Parkway, Redwood Shores, CA', ',[^,]+,') RESULT FROM dual; Look for http:// followed by a substring of one or more alphanumeric characters and optionally, a period (.) col result format a50 SELECT REGEXP_SUBSTR('Go to http://www.oracle.com/products and click on database', 'http://([[:alnum:]]+\.?){3,4}/?') RESULT FROM dual; Extracts try, trying, tried or tries SELECT REGEXP_SUBSTR('We are trying to make the subject easier.','tr(y(ing)?|(ied)|(ies))') FROM dual; Extract the 3rd field treating ':' as a delimiter SELECT REGEXP_SUBSTR('system/pwd@orabase:1521:sidval', '[^:]+', 1, 3) RESULT FROM dual; Extract from string with vertical bar delimiter CREATE TABLE regexp ( testcol VARCHAR2(50)); INSERT INTO regexp (testcol) VALUES ('One|Two|Three|Four|Five'); SELECT * FROM regexp; SELECT REGEXP_SUBSTR(testcol,'[^|]+', 1, 3) FROM regexp; Equivalence classes SELECT REGEXP_SUBSTR('iSelfSchooling NOT ISelfSchooling', '[[=i=]]SelfSchooling') RESULT FROM dual; Parsing Demo set serveroutput on DECLARE x VARCHAR2(2); y VARCHAR2(2); c VARCHAR2(40) := '1:3,4:6,8:10,3:4,7:6,11:12'; BEGIN x := REGEXP_SUBSTR(c,'[^:]+', 1, 1); y := REGEXP_SUBSTR(c,'[^,]+', 3, 1); dbms_output.put_line(x ||' '|| y); END; / |
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