oralce正则表达式函数

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Oracle Regular Expressions

Version 11.1

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 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 ä and â. The equivalence classes are valid only inside the bracketed expression 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 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 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 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 Demo Table CREATETABLEtest ( testcolVARCHAR2(50)); INSERTINTOtestVALUES('abcde'); INSERTINTOtestVALUES('12345'); INSERTINTOtestVALUES('1a4A5'); INSERTINTOtestVALUES('12a45'); INSERTINTOtestVALUES('12aBC'); INSERTINTOtestVALUES('12abc'); INSERTINTOtestVALUES('12ab5'); INSERTINTOtestVALUES('12aa5'); INSERTINTOtestVALUES('12AB5'); INSERTINTOtestVALUES('ABCDE'); INSERTINTOtestVALUES('123-5'); INSERTINTOtestVALUES('12.45'); INSERTINTOtestVALUES('1a4b5'); INSERTINTOtestVALUES('1 3 5'); INSERTINTOtestVALUES('1 45'); INSERTINTOtestVALUES('1 5'); INSERTINTOtestVALUES('a b c d'); INSERTINTOtestVALUES('a b c d e'); INSERTINTOtestVALUES('a e'); INSERTINTOtestVALUES('Steven'); INSERTINTOtestVALUES('Stephen'); INSERTINTOtestVALUES('111.222.3333'); INSERTINTOtestVALUES('222.333.4444'); INSERTINTOtestVALUES('333.444.5555'); INSERTINTOtestVALUES('abcdefabcdefabcxyz'); COMMIT; REGEXP_COUNT Syntax REGEXP_COUNT(<source_string>,<pattern>[[,<start_position>],[<match_parameter>]]) -- 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 characters Count's occurrences based on a regular expression SELECTREGEXP_COUNT(testcol,'2a',1,'i') RESULT FROMtest; SELECTREGEXP_COUNT(testcol,'e','i') RESULT FROMtest; REGEXP_INSTR Syntax REGEXP_INSTR(<source_string>,<start_position>][,<occurrence>][,<return_option>][,<match_parameter>][,<sub_expression>]]) Find character 'o' followed by any 3 alphabetic characters: case insensitive Our thanks to Cassio for spotting a typo here. SELECTREGEXP_INSTR('500Oracle Pkwy,Redwood Shores,CA','[o][[:alpha:]]{3}','i') RESULT FROMDUAL; SELECTREGEXP_INSTR('500 OraclePkwy,'i') RESULT FROMDUAL; SELECTREGEXP_INSTR('500 Oracle Pkwy,Redwood Shores,2,Redwood Shores,CA','i') RESULT FROMDUAL; Find the position of try,trying,tried or tries SELECTREGEXP_INSTR('We are trying to make the subject easier.','tr(y(ing)?|(ied)|(ies))') RESULTNUM FROMDUAL; Using Sub-Expression option SELECTtestcol,REGEXP_INSTR(testcol,'ab','i',0) FROMtest; SELECTtestcol,1) FROMtest; SELECTtestcol,'a(b)',1) FROMtest; REGEXP_LIKE Syntax REGEXP_LIKE(<source_string>,<pattern>,<match_parameter>) AlphaNumeric Characters SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:alnum:]]'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:alnum:]]{3}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:alnum:]]{5}'); Alphabetic Characters SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:alpha:]]'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:alpha:]]{3}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:alpha:]]{5}'); Control Characters INSERTINTOtestVALUES('zyx' ||CHR(13) || 'wvu'); COMMIT; SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:cntrl:]]{1}'); Digits SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:digit:]]'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:digit:]]{3}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:digit:]]{5}'); Lower Case SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:lower:]]'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:lower:]]{2}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:lower:]]{3}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:lower:]]{5}'); Printable Characters SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:print:]]{5}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:print:]]{6}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:print:]]{7}'); Punctuation TRUNCATETABLEtest; SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:punct:]]'); Spaces SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:space:]]'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:space:]]{2}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:space:]]{3}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:space:]]{5}'); Upper Case SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:upper:]]'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:upper:]]{2}'); SELECT* FROMtest WHEREREGEXP_LIKE(testcol,'[[:upper:]]{3}'); Values Starting with 'a%b' SELECTtestcol FROMtest WHEREREGEXP_LIKE(testcol,'^ab*'); 'a' is the third value SELECTtestcol FROMtest WHEREREGEXP_LIKE(testcol,'^..a.'); Contains two consecutive occurances of the letter 'a' or 'z' SELECTtestcol FROMtest WHEREREGEXP_LIKE(testcol,'([az])\1','i'); Begins with 'Ste' ends with 'en' and contains either 'v' or 'ph' in the center SELECTtestcol FROMtest WHEREREGEXP_LIKE(testcol,'^Ste(v|ph)en$'); Use a regular expression in a check constraint CREATETABLEmytest (c1VARCHAR2(20), CHECK (REGEXP_LIKE(c1,'^[[:alpha:]]+$'))); Identify SSN Thanks: Byron Bush HIoUG CREATETABLEssn_test ( ssn_colVARCHAR2(20)); INSERTINTOssn_testVALUES('111-22-3333'); INSERTINTOssn_testVALUES('111=22-3333'); INSERTINTOssn_testVALUES('111-A2-3333'); INSERTINTOssn_testVALUES('111-22-33339'); INSERTINTOssn_testVALUES('111-2-23333'); INSERTINTOssn_testVALUES('987-65-4321'); COMMIT; SELECTssn_col from ssn_test WHEREREGEXP_LIKE(ssn_col,'^[0-9]{3}-[0-9]{2}-[0-9]{4}$'); REGEXP_REPLACE Syntax REGEXP_REPLACE(<source_string>, <replace_string>,<position>,<occurrence>,<match_parameter>) Looks for the pattern xxx.xxx.xxxx and reformats pattern to (xxx) xxx-xxxx col testcol format a15 col result format a15 SELECTtestcol,REGEXP_REPLACE(testcol, '([[:digit:]]{3})\.([[:digit:]]{3})\.([[:digit:]]{4})', '(\1) \2-\3') RESULT FROMtest WHERELENGTH(testcol) = 12; Put a space after every character SELECTtestcol,'(.)','\1 ') RESULT FROMtest WHEREtestcol like 'S%'; Replace multiple spaces with a single space SELECTREGEXP_REPLACE('500 Oracle Parkway,'( ){2,}',' ') RESULT FROMDUAL; Insert a space between a lower case character followed by an upper case character SELECTREGEXP_REPLACE('George McGovern','([[:lower:]])([[:upper:]])','\1 \2') CITY FROMDUAL; (Produces 'George Mc Govern') Replace the period with a string (note use of '\') SELECTREGEXP_REPLACE('We are trying to make the subject easier.','\.',' for you.') REGEXT_SAMPLE FROMDUAL; Demo CREATETABLEt( testcolVARCHAR2(10)); INSERTINTOtVALUES('1'); INSERTINTOtVALUES('2 '); INSERTINTOtVALUES('3 new '); col newval format a10 SELECTLENGTH(testcol) len,testcol origval, REGEXP_REPLACE(testcol,'\W+$',' ') newval, LENGTH(REGEXP_REPLACE(testcol,' ')) newlen FROMt; Code snippet courtesy of Valentin Matak. This is a handy way to remove duplicate characters from a string. This example shows the 1+ repeatability qualifier in use. SELECTREGEXP_REPLACE('ABBBCABBCCCAABAAAAA','(A|B|C)\1+','\1') FROMDUAL; Code snippet courtesy of Jonathan Linder. This checks for a valid email address and then extracts the domain name. SELECTREGEXP_REPLACE('[e-mail]','^(\S+)@(\S+)','\2') FROMDUALd WHERE REGEXP_LIKE('[e-mail]','^[A-Za-z0-9._%+-]+@([A-Za-z0-9-]+.)?+[A-Za-z]{2,63}$') Code snippet courtesy of Juraj Drusc. This example will convert Oracle's SYS_GUID() to a JAVA UUID. SELECTlower(REGEXP_REPLACE(sys_guid(), '([[:alnum:]]{8})([[:alnum:]]{4})([[:alnum:]]{4})([[:alnum:]]{4})([[:alnum:]]{12})', '1-2-3-4-5'))FROMDUAL; REGEXP_SUBSTR Syntax 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 SELECTREGEXP_SUBSTR('500 Oracle Parkway,',[^,]+,') RESULT FROMDUAL; Look for http:// followed by a substring of one or more alphanumeric characters and optionally,a period (.) col result format a50 SELECTREGEXP_SUBSTR('Go to http://www.oracle.com/products and click on database', 'http://([[:alnum:]]+\.?){3,4}/?') RESULT FROMDUAL; Extracts try,tried or tries SELECTREGEXP_SUBSTR('We are trying to make the subject easier.','tr(y(ing)?|(ied)|(ies))') FROMDUAL; Extract the 3rd field treating ':' as a delimiter SELECTREGEXP_SUBSTR('system/pwd@orabase:1521:sidval', '[^:]+',3) RESULT FROMDUAL; Extract from string with vertical bar delimiter CREATETABLEregexp ( testcolVARCHAR2(50)); INSERTINTOregexp (testcol) VALUES ('One|Two|Three|Four|Five'); SELECT*FROMregexp; SELECTREGEXP_SUBSTR(testcol,'[^|]+',3) FROMregexp; Equivalence classes SELECTREGEXP_SUBSTR('iSelfSchooling NOT ISelfSchooling','[[=i=]]SelfSchooling') RESULT FROMDUAL; Parsing Demo set serveroutput on DECLARE xVARCHAR2(2); yVARCHAR2(2); cVARCHAR2(40) := '1:3,4:6,8:10,3:4,7:6,11:12'; BEGIN x := REGEXP_SUBSTR(c,'[^:]+',1); y := REGEXP_SUBSTR(c,'[^,]+',3,1); dbms_output.put_line(x ||' '|| y); END; / Gary Whitaker wrote in with an addition to this parsing demo,and had the following comments: The parsing demo above uses the regular expression '[^,]+' whichdoes not workwhen there is aNULLelement in the list. This Could result in returning the wrong element's data. Consider this simple example with comments: set serveroutput on DECLARE xVARCHAR2(1); yVARCHAR2(1); zVARCHAR2(1); cVARCHAR2(40) := '1,4,5,6,7'; BEGIN -- Works as expected if the value you seek is before any null value in the list: x := REGEXP_SUBSTR(c,2); -- This form only returns the 4th element when all elements are present. -- It will return the 4thnon-nullelement,which in this example is really '5', -- which Could be misleading. -- if you are really after the 4th element regardless if there is a null element: y := REGEXP_SUBSTR(c,4); -- This form gets the actual 4th element,allowing for the null element. -- Get the 1st substring of the 4th instance of a set of characters that are not a comma,-- when followed by a comma or the end of the line: z := REGEXP_SUBSTR(c,'([^,]*)(,|$)',NULL,1); dbms_output.put_line(x); dbms_output.put_line(y); dbms_output.put_line(z); END; /