Fun fun regular expressions

My goal: to create a regular expression that will match a four character hexadecimal value that is left-padded with spaces.
Examples:" 1", " A4", " 51C", "FFAB"All the alpha characters will be uppercase.
My solution:"[0-9A-F]{4}| [0-9A-F]{3}| [0-9A-F]{2}| [0-9A-F]"My question is:
Is there a more concise way to represent this? I am parsing a line of text that is formatted into columns and delimited with spaces, so this is actually a subexpression in a capturing group and the spaces are important.
Thank you for any help you can provide.

It's not easy, taken out of context, had to put the two delimiting spaces in to get a grip.
I can make an alternative regex, but it is not "better" as such.
Sorry for using perl, but when people talk regex ...#!/bin/perl/bin/perl.exe
use strict;
$^W = 1;
$\ = "\n";
my (@good) = ( " 1", " AB", " 123", "cafe", );
my (@bad) = ("123 ", " ", "123", "12345", "gggg", " 123", " ", "",
 "a a ", " a a", "1 1", );
my $s;
for $s (@good) {
 ismatch($s);
for $s (@bad) {
 ismatch($s);
sub ismatch {
 $_ = ' '.$_[0].' ';
 # if (/^ ([\dA-Fa-f]{4}| [\dA-Fa-f]{3}| [\dA-Fa-f]{2}| [\dA-Fa-f]) $/) {
 if (/^ (?! *[\d\w]+ +[\d\w])[ \dA-Fa-f]{4}(?<! ) $/) {
 print "Match: \"$_\"";
 else {
 print "No match: \"$_\"";
}

Similar Messages

Introduction to regular expressions ...

I'm well aware that there are already some articles on that topic, some people asked me to share some of my knowledge on this topic. Please take a look at this first part and let me know if you find this useful. If yes, I'm going to continue on writing more parts using more and more complicated expressions - if you have questions or problems that you think could be solved through regular expression, please post them.
Introduction
Oracle has always provided some character/string functions in its PL/SQL command set, such as SUBSTR, REPLACE or TRANSLATE. With 10g, Oracle finally gave us, the users, the developers and of course the DBAs regular expressions. However, regular expressions, due to their sometimes cryptic rules, seem to be overlooked quite often, despite the existence of some very interesing use cases. Beeing one of the advocates of regular expression, I thought I'll give the interested audience an introduction to these new functions in several installments.
Having fun with regular expressions - Part 1
Oracle offers the use of regular expression through several functions: REGEXP_INSTR, REGEXP_SUBSTR, REGEXP_REPLACE and REGEXP_LIKE. The second part of each function already gives away its purpose: INSTR for finding a position inside a string, SUBSTR for extracting a part of a string, REPLACE for replacing parts of a string. REGEXP_LIKE is a special case since it could be compared to the LIKE operator and is therefore usually used in comparisons like IF statements or WHERE clauses.
Regular expressions excel, in my opinion, in search and extraction of strings, using that for finding or replacing certain strings or check for certain formatting criterias. They're not very good at formatting strings itself, except for some special cases I'm going to demonstrate.
If you're not familiar with regular expression, you should take a look at the definition in Oracle's user guide Using Regular Expressions With Oracle Database, and please note that there have been some changes and advancements in 10g2. I'll provide examples, that should work on both versions.
Some of you probably already encountered this problem: checking a number inside a string, because, for whatever reason, a column was defined as VARCHAR2 and not as NUMBER as one would have expected.
Let's check for all rows where column col1 does NOT include an unsigned integer. I'll use this SELECT for demonstrating different values and search patterns:
WITH t AS (SELECT '456' col1
             FROM dual
            UNION
           SELECT '123x'
             FROM dual
            UNION
           SELECT 'x123'
             FROM dual
            UNION
           SELECT 'y'
             FROM dual
            UNION
           SELECT '+789'
             FROM dual
            UNION
           SELECT '-789'
             FROM dual
            UNION
           SELECT '159-'
             FROM dual
            UNION
           SELECT '-1-'
             FROM dual
SELECT t.col1
FROM t
WHERE NOT REGEXP_LIKE(t.col1, '^[0-9]+$')
;Let's take a look at the 2nd argument of this REGEXP function: '^[0-9]+$'. Translated it would mean: start at the beginning of the string, check if there's one or more characters in the range between '0' and '9' (also called a matching character list) until the end of this string. "^", "[", "]", "+", "$" are all Metacharacters.
To understand regular expressions, you have to "think" in regular expressions. Each regular expression tries to "fit" an available string into its pattern and returns a result beeing successful or not, depending on the function. The "art" of using regular expressions is to construct the right search pattern for a certain task. Using functions like TRANSLATE or REPLACE did already teach you using search patterns, regular expressions are just an extension to this paradigma. Another side note: most of the search patterns are placeholders for single characters, not strings.
I'll take this example a bit further. What would happen if we would remove the "$" in our example? "$" means: (until the) end of a string. Without this, this expression would only search digits from the beginning until it encounters either another character or the end of the string. So this time, '123x' would be removed from the SELECTION since it does fit into the pattern.
Another change: we will keep the "$" but remove the "^". This character has several meanings, but in this case it declares: (start from the) beginning of a string. Without it, the function will search for a part of a string that has only digits until the end of the searched string. 'x123' would now be removed from our selection.
Now there's a question: what happens if I remove both, "^" and "$"? Well, just think about it. We now ask to find any string that contains at least one or more digits, so both '123x' and 'x123' will not show up in the result.
So what if I want to look for signed integer, since "+" is also used for a search expression. Escaping is the name of the game. We'll just use '^\+[0-9]+$' Did you notice the "\" before the first "+"? This is now a search pattern for the plus sign.
Should signed integers include negative numbers as well? Of course they should, and I'll once again use a matching character list. In this list, I don't need to do escaping, although it is possible. The result string would now look like this: '^[+-]?[0-9]+$'. Did you notice the "?"? This is another metacharacter that changes the placeholder for plus and minus to an optional placeholder, which means: if there's a "+" or "-", that's ok, if there's none, that's also ok. Only if there's a different character, then again the search pattern will fail.
Addendum: From this on, I found a mistake in my examples. If you would have tested my old examples with test data that would have included multiple signs strings, like "--", "-+", "++", they would have been filtered by the SELECT statement. I mistakenly used the "*" instead of the "?" operator. The reason why this is a bad idea, can also be found in the user guide: the "*" meta character is defined as 0 to multiple occurrences.
Looking at the values, one could ask the question: what about the integers with a trailing sign? Quite simple, right? Let's just add another '[+-] and the search pattern would look like this: '^[+-]?[0-9]+[+-]?$'.
Wait a minute, what happened to the row with the column value "-1-"?
You probably already guessed it: the new pattern qualifies this one also as a valid string. I could now split this pattern into several conditions combined through a logical OR, but there's something even better: a logical OR inside the regular expression. It's symbol is "|", the pipe sign.
Changing the search pattern again to something like this '^[+-]?[0-9]+$|^[0-9]+[+-]?$' [1] would return now the "-1-" value. Do I have to duplicate the same elements like "^" and "$", what about more complicated, repeating elements in future examples? That's where subexpressions/grouping comes into play. If I want only certain parts of the search pattern using an OR operator, we can put those inside round brackets. '^([+-]?[0-9]+|[0-9]+[+-]?)$' serves the same purpose and allows for further checks without duplicating the whole pattern.
Now looking for integers is nice, but what about decimal numbers? Those may be a bit more complicated, but all I have to do is again to think in (meta) characters. I'll just use an example where the decimal point is represented by ".", which again needs escaping, since it's also the place holder in regular expressions for "any character".
Valid decimals in my example would be ".0", "0.0", "0.", "0" (integer of course) but not ".". If you want, you can test it with the TO_NUMBER function. Finding such an unsigned decimal number could then be formulated like this: from the beginning of a string we will either allow a decimal point plus any number of digits OR at least one digits plus an optional decimal point followed by optional any number of digits. Think about it for a minute, how would you formulate such a search pattern?
Compare your solution to this one:
'^(\.[0-9]+|[0-9]+(\.[0-9]*)?)$'
Addendum: Here I have to use both "?" and "*" to make sure, that I can have 0 to many digits after the decimal point, but only 0 to 1 occurrence of this substrings. Otherwise, strings like "1.9.9.9" would be possible, if I would write it like this:
'^(\.[0-9]+|[0-9]+(\.[0-9]*)*)$'Some of you now might say: Hey, what about signed decimal numbers? You could of course combine all the ideas so far and you will end up with a very long and almost unreadable search pattern, or you start combining several regular expression functions. Think about it: Why put all the search patterns into one function? Why not split those into several steps like "check for a valid decimal" and "check for sign".
I'll just use another SELECT to show what I want to do:
WITH t AS (SELECT '0' col1
             FROM dual
            UNION
           SELECT '0.'
             FROM dual
            UNION
           SELECT '.0'
             FROM dual
            UNION
           SELECT '0.0'
             FROM dual
            UNION
           SELECT '-1.0'
             FROM dual
            UNION
           SELECT '.1-'
             FROM dual
            UNION
           SELECT '.'
             FROM dual
            UNION
           SELECT '-1.1-'
             FROM dual
SELECT t.*
FROM t
;From this select, the only rows I need to find are those with the column values "." and "-1.1-". I'll start this with a check for valid signs. Since I want to combine this with the check for valid decimals, I'll first try to extract a substring with valid signs through the REGEXP_SUBSTR function:
NVL(REGEXP_SUBSTR(t.col1, '^([+-]?[^+-]+|[^+-]+[+-]?)$'), ' ')Remember the OR operator and the matching character collections? But several "^"? Some of the meta characters inside a search pattern can have different meanings, depending on their positions and combination with other meta characters. In this case, the pattern translates into: from the beginning of the string search for "+" or "-" followed by at least another character that is not "+" or "-". The second pattern after the "|" OR operator does the same for a sign at the end of the string.
This only checks for a sign but not if there also only digits and a decimal point inside the string. If the search string fails, for example when we have more than one sign like in the "-1.1-", the function returns NULL. NULL and LIKE don't go together very well, so we'll just add NVL with a default value that tells the LIKE to ignore this string, in this case a space.
All we have to do now is to combine the check for the sign and the check for a valid decimal number, but don't forget an option for the signs at the beginning or end of the string, otherwise your second check will fail on the signed decimals. Are you ready?
Does your solution look a bit like this?
WHERE NOT REGEXP_LIKE(NVL(REGEXP_SUBSTR(t.col1,
                           '^([+-]?[^+-]+|[^+-]+[+-]?)$'),
                       '^[+-]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)[+-]?$'
                      )Now the optional sign checks in the REGEXP_LIKE argument can be added to both ends, since the SUBSTR won't allow any string with signs on both ends. Thinking in regular expression again.
Continued in Introduction to regular expressions ... continued.
C.
Fixed some embarrassing typos ... and mistakes.
cd

Excellent write up CD. Very nice indeed. Hopefully you'll be completing parts 2 and 3 some time soon. And with any luck, your article will encourage others to do the same....I know there's a few I'd like to see and a few I'd like to have a go at writing too :-)

Introduction to regular expressions ... continued.

After some very positive feedback from Introduction to regular expressions ... I'm now continuing on this topic for the interested audience. As always, if you have questions or problems that you think could be solved through regular expression, please post them.
Having fun with regular expressions - Part 2
Finishing my example with decimal numbers, I thought about a method to test regular expressions. A question from another user who was looking for a way to show all possible combinations inspired me in writing a small package.
CREATE OR REPLACE PACKAGE regex_utils AS
-- Regular Expression Utilities
-- Version 0.1
TYPE t_outrec IS RECORD(
 data VARCHAR2(255)
TYPE t_outtab IS TABLE OF t_outrec;
FUNCTION gen_data(
 p_charset IN VARCHAR2 -- character set that is used for generation
, p_length IN NUMBER -- length of the generated
) RETURN t_outtab PIPELINED;
END regex_utils;
CREATE OR REPLACE PACKAGE BODY regex_utils AS
-- FUNCTION gen_data returns a collection of generated varchar2 elements
FUNCTION gen_data(
 p_charset IN VARCHAR2 -- character set that is used for generation
, p_length IN NUMBER -- length of the generated
) RETURN t_outtab PIPELINED
IS
 TYPE t_counter IS TABLE OF PLS_INTEGER INDEX BY PLS_INTEGER;
 v_counter t_counter;
 v_exit BOOLEAN;
 v_string VARCHAR2(255);
 v_outrec t_outrec;
BEGIN
 FOR max_length IN 1..p_length
 LOOP
 -- init counter loop
 FOR i IN 1..max_length
 LOOP
 v_counter(i) := 1;
 END LOOP;
 -- start data generation loop
 v_exit := FALSE;
 WHILE NOT v_exit
 LOOP
 -- start generation
 v_string := '';
 FOR i IN 1..max_length
 LOOP
 v_string := v_string || SUBSTR(p_charset, v_counter(i), 1);
 END LOOP;
 -- set outgoing record
 v_outrec.data := v_string;
 -- now pipe the result
 PIPE ROW(v_outrec);
 -- increment loop
 <<inc_loop>>
 FOR i IN REVERSE 1..max_length
 LOOP
 v_counter(i) := v_counter(i) + 1;
 IF v_counter(i) > LENGTH(p_charset) THEN
 IF i > 1 THEN
 v_counter(i) := 1;
 ELSE
 v_exit := TRUE;
 END IF;
 ELSE
 -- no further processing required
 EXIT inc_loop;
 END IF;
 END LOOP;
 END LOOP;
 END LOOP;
END gen_data;
END regex_utils;
/This package is a brute force string generator using all possible combinations of a characters in a string up to a maximum length. Together with the regular expressions, I can now show what combinations my solution would allow to pass. But see for yourself:
SELECT *
FROM (SELECT data col1
 FROM TABLE(regex_utils.gen_data('+-.0', 5))
 ) t
WHERE REGEXP_LIKE(NVL(REGEXP_SUBSTR(t.col1,
 '^([+-]?[^+-]+|[^+-]+[+-]?)$'
 '^[+-]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)[+-]?$'
;You will see some results, which are perfectly valid for my definition of decimal numbers but haven't been mentioned, like '000' or '+.00'. From now on I will also use this package to verify the solutions I'll present to you and hopefully reduce my share of typos.
Counting and finding certain characters or words in a string can be a tedious task. I'll show you how it's done with regular expressions. I'll start with an easy example, count all spaces in the string "Having fun with regular expressions.":
SELECT NVL(LENGTH(REGEXP_REPLACE('Having fun with regular expressions', '[^ ]')), 0)
FROM dual
;No surprise there. I'm replacing all characters except spaces with a null string. Since REGEXP_REPLACE assumes a NULL string as replacement argument, I can save on adding a third argument, which would look like this:
REGEXP_REPLACE('Having fun with regular expressions', '[^ ]', '')So REPLACE will return all the spaces which we can count with the LENGTH function. If there aren't any, I will get a NULL string, which is checked by the NVL function. If you want you can play around by changing the space character to somethin else.
A variation of this theme could be counting the number of words. Counting spaces and adding 1 to this result could be misleading if there are duplicate spaces. Thanks to regular expressions, I can of course eliminate duplicates.
Using the old method on the string "Having fun with regular expressions" would return anything but the right number. This is, where Backreferences come into play. REGEXP_REPLACE uses them in the replacement argument, a backslash plus a single digit, like this: '\1'. To reference a string in a search pattern, I have to use subexpressions (remember the round brackets?).
SELECT NVL(LENGTH(REGEXP_REPLACE('Having fun with regular expressions', '( )\1*|.', '\1')))
FROM dual
;You may have noticed that I changed from using the "^" as a NOT operator to using the "|" OR operator and the "." any character placeholder. This neat little trick allows to filter all other characters except the one we're looking in the first place. "\1" as backreference is outside of our subexpression since I don't want to count the trailing spaces and is used both in the search pattern and the replacement argument.
Still I'm not satisfied with this: What about leading/trailing blanks, what if there are any special characters, numbers, etc.? Finally, it's time to only count words. For the purpose of this demonstration, I define a word as one or more consecutive letters. If by now you're already thinking in regular expressions, the solution is not far away. One hint: you may want to check on the "i" match parameter which allows for case insensitive search. Another one: You won't need a back reference in the search pattern this time.
Let's compare our solutions than, shall we?
SELECT NVL(LENGTH(REGEXP_REPLACE('Having fun with regular expressions. !',
 '([a-z])+|.', '\1', 1, 0, 'i')), 0)
FROM dual;This time I don't use a backreference, the "+" operator (remember? 1 or more) will suffice. And since I want to count the occurences, not the letters, I moved the "+" meta character outside of the subexpression. The "|." trick again proved to be useful.
Case insensitive search does have its merits. It will only search but not transform the any found substring. If I want, for example, extract any occurence of the word fun, I'll just use the "i" match parameter and get this substring, whether it's written as "Fun", "FUN" or "fun". Can be very useful if you're looking for example for names of customers, streets, etc.
Enough about counting, how about finding? What if I want to know the last occurence of a certain character or string, for example the postition of the last space in this string "Where is the last space?"?
Addendum: Thanks to another forum member, I should mention that using the INSTR function can do a reverse search by itself.[i]
WITH t AS (SELECT 'Where is the last space?' col1
 FROM dual)
SELECT INSTR(col1, ' ', -1)
FROM DUAL;Now regular expressions are powerful, but there is no parameter that allows us to reverse the search direction. However, remembering that we have the "$" meta character that means (until the) end of string, all I have to do is use a search pattern that looks for a combination of space and non-space characters including the end of a string. Now compare the REGEXP_INSTR function to the previous solution:
SELECT REGEXP_INSTR(t.col1, ' [^ ]*$')
FROM t;So in this case, it'll remain a matter of taste what you want to use. If the search pattern has to look for the last occurrence of another regular expression, this is the way to solve such a requirement.
One more thing about backreferences. They can be used for a sort of primitive "string swapping". If for example you have to transform column values like swapping first and last name, backreferenc is your friend. Here's an example:
SELECT REGEXP_REPLACE('John Doe', '^(.*) (.*)$', '\2, \1')
FROM dual
;What about middle names, for example 'John J. Doe'? Look for yourself, it still works.
You can even use that for strings with delimiters, for example reversing delimited "fields" like in this string '10~20~30~40~50' into '50~40~30~20~10'. Using REVERSE, I would get '05~04~03~02~01', so there has to be another way. Using backreferences however is limited to 9 subexpressions, which limits the following solution a bit, if you need to process strings with more than 9 fields. If you want, you can think this example through and see if your solution matches mine.
SELECT REGEXP_REPLACE('10~20~30~40~50',
 '^(.*)~(.*)~(.*)~(.*)~(.*)$',
 '\5~\4~\3~\2~\1'
FROM dual;After what you've learned so far, that wasn't too hard, was it? Enough for now ...
Continued in Introduction to regular expressions ... last part..
C.
Fixed some typos and a flawed example ...
cd

Thank you very much C. Awaiting other parts.... keep going.
One german typo :-)
I'm replacing all characters except spaces mit anull string.I received a functional spec from my Dutch analyst in which it is written
tnsnames voor EDWH:
PCESCRD1 = (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)
 (HOST=blah.blah.blah.com)
 (PORT=5227)))
 (CONNECT_DATA=(SID=pcescrd1)))
db user: BW_I2_VIEWER / BW_I2_VIEWER_SCRD1Had to look for translators.
Cheers
Sarma.

Introduction to regular expressions ... last part.

Continued from Introduction to regular expressions ... continued., here's the third and final part of my introduction to regular expressions. As always, if you find mistakes or have examples that you think could be solved through regular expressions, please post them.
Having fun with regular expressions - Part 3
In some cases, I may have to search for different values in the same column. If the searched values are fixed, I can use the logical OR operator or the IN clause, like in this example (using my brute force data generator from part 2):
SELECT data
FROM TABLE(regex_utils.gen_data('abcxyz012', 4))
WHERE data IN ('abc', 'xyz', '012');There are of course some workarounds as presented in this asktom thread but for a quick solution, there's of course an alternative approach available. Remember the "|" pipe symbol as OR operator inside regular expressions? Take a look at this:
SELECT data
FROM TABLE(regex_utils.gen_data('abcxyz012', 4))
WHERE REGEXP_LIKE(data, '^(abc|xyz|012)$')
;I can even use strings composed of values like 'abc, xyz , 012' by simply using another regular expression to replace "," and spaces with the "|" pipe symbol. After reading part 1 and 2 that shouldn't be too hard, right? Here's my "thinking in regular expression": Replace every "," and 0 or more leading/trailing spaces.
Ready to try your own solution?
Does it look like this?
SELECT data
FROM TABLE(regex_utils.gen_data('abcxyz012', 4))
WHERE REGEXP_LIKE(data, '^(' || REGEXP_REPLACE('abc, xyz , 012', ' *, *', '|') || ')$')
;If I wouldn't use the "^" and "$" metacharacter, this SELECT would search for any occurence inside the data column, which could be useful if I wanted to combine LIKE and IN clause. Take a look at this example where I'm looking for 'abc%', 'xyz%' or '012%' and adding a case insensitive match parameter to it:
SELECT data
FROM TABLE(regex_utils.gen_data('abcxyz012', 4))
WHERE REGEXP_LIKE(data, '^(abc|xyz|012)', 'i')
; An equivalent non regular expression solution would have to look like this, not mentioning other options with adding an extra "," and using the INSTR function:
SELECT data
FROM (SELECT data, LOWER(DATA) search
          FROM TABLE(regex_utils.gen_data('abcxyz012', 4))
WHERE search LIKE 'abc%'
    OR search LIKE 'xyz%'
    OR search LIKE '012%'
SELECT data
FROM (SELECT data, SUBSTR(LOWER(DATA), 1, 3) search
          FROM TABLE(regex_utils.gen_data('abcxyz012', 4))
WHERE search IN ('abc', 'xyz', '012')
; I'll leave it to your imagination how a complete non regular example with 'abc, xyz , 012' as search condition would look like.
As mentioned in the first part, regular expressions are not very good at formatting, except for some selected examples, such as phone numbers, which in my demonstration, have different formats. Using regular expressions, I can change them to a uniform representation:
WITH t AS (SELECT '123-4567' phone
             FROM dual
            UNION
           SELECT '01 345678'
             FROM dual
            UNION
           SELECT '7 87 8787'
             FROM dual
SELECT t.phone, REGEXP_REPLACE(REGEXP_REPLACE(phone, '[^0-9]'), '(.{3})(.*)', '(\1)-\2')
FROM t
;First, all non digit characters are beeing filtered, afterwards the remaining string is put into a "(xxx)-xxxx" format, but not cutting off any phone numbers that have more than 7 digits. Using such a conversion could also be used to check the validity of entered data, and updating the value with a uniform format afterwards.
Thinking about it, why not use regular expressions to check other values about their formats? How about an IP4 address? I'll do this step by step, using 127.0.0.1 as the final test case.
First I want to make sure, that each of the 4 parts of an IP address remains in the range between 0-255. Regular expressions are good at string matching but they don't allow any numeric comparisons. What valid strings do I have to take into consideration?
Single digit values: 0-9
Double digit values: 00-99
Triple digit values: 000-199, 200-255 (this one will be the trickiest part)
So far, I will have to use the "|" pipe operator to match all of the allowed combinations. I'll use my brute force generator to check if my solution works for a single value:
SELECT data
FROM TABLE(regex_utils.gen_data('0123456789', 3))
WHERE REGEXP_LIKE(data, '^(25[0-5]|2[0-4][0-9]|[01]?[0-9]{1,2})$')
; More than 255 records? Leading zeros are allowed, but checking on all the records, there's no value above 255. First step accomplished. The second part is to make sure, that there are 4 such values, delimited by a "." dot. So I have to check for 0-255 plus a dot 3 times and then check for another 0-255 value. Doesn't sound to complicated, does it?
Using first my brute force generator, I'll check if I've missed any possible combination:
SELECT data
FROM TABLE(regex_utils.gen_data('03.', 15))
WHERE REGEXP_LIKE(data,
                   '^((25[0-5]|2[0-4][0-9]|[01]?[0-9]{1,2})\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9]{1,2})$'
; Looks good to me. Let's check on some sample data:
WITH t AS (SELECT '127.0.0.1' ip
             FROM dual
            UNION
           SELECT '256.128.64.32'
             FROM dual
SELECT t.ip
FROM t WHERE REGEXP_LIKE(t.ip,
                   '^((25[0-5]|2[0-4][0-9]|[01]?[0-9]{1,2})\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9]{1,2})$'
; No surprises here. I can take this example a bit further and try to format valid addresses to a uniform representation, as shown in the phone number example. My goal is to display every ip address in the "xxx.xxx.xxx.xxx" format, using leading zeros for 2 and 1 digit values.
Regular expressions don't have any format models like for example the TO_CHAR function, so how could this be achieved? Thinking in regular expressions, I first have to find a way to make sure, that each single number is at least three digits wide. Using my example, this could look like this:
WITH t AS (SELECT '127.0.0.1' ip
             FROM dual
SELECT t.ip, REGEXP_REPLACE(t.ip, '([0-9]+)(\.?)', '00\1\2')
FROM t
; Look at this: leading zeros. However, that first value "00127" doesn't look to good, does it? If you thought about using a second regular expression function to remove any excess zeros, you're absolutely right. Just take the past examples and think in regular expressions. Did you come up with something like this?
WITH t AS (SELECT '127.0.0.1' ip
             FROM dual
SELECT t.ip, REGEXP_REPLACE(REGEXP_REPLACE(t.ip, '([0-9]+)(\.?)', '00\1\2'),
                            '[0-9]*([0-9]{3})(\.?)', '\1\2'
FROM t
; Think about the possibilities: Now you can sort a table with unformatted IP addresses, if that is a requirement in your application or you find other values where you can use that "trick".
Since I'm on checking INET (internet) type of values, let's do some more, for example an e-mail address. I'll keep it simple and will only check on the
"[email protected]", "[email protected]" and "[email protected]" format, where x represents an alphanumeric character. If you want, you can look up the corresponding RFC definition and try to build your own regular expression for that one.
Now back to this one: At least one alphanumeric character followed by an "@" at sign which is followed by at least one alphanumeric character followed by a "." dot and exactly 3 more alphanumeric characters or 2 more characters followed by a "." dot and another 2 characters. This should be an easy one, right? Use some sample e-mail addresses and my brute force generator, you should be able to verify your solution.
Here's mine:
SELECT data
FROM TABLE(regex_utils.gen_data('a1@.', 9))
WHERE REGEXP_LIKE(data, '^[[:alnum:]]+@[[:alnum:]]+(\.[[:alnum:]]{3,4}|(\.[[:alnum:]]{2}){2})$', 'i'); Checking on valid domains, in my opinion, should be done in a second function, to keep the checks by itself simple, but that's probably a discussion about readability and taste.
How about checking a valid URL? I can reuse some parts of the e-mail example and only have to decide what type of URLs I want, for example "http://", "https://" and "ftp://", any subdomain and a "/" after the domain. Using the case insensitive match parameter, this shouldn't take too long, and I can use this thread's URL as a test value. But take a minute to figure that one out for yourself.
Does it look like this?
WITH t AS (SELECT 'Introduction to regular expressions ... last part. URL
             FROM dual
            UNION
           SELECT 'http://x/'
             FROM dual
SELECT t.URL
FROM t
WHERE REGEXP_LIKE(t.URL, '^(https*|ftp)://(.+\.)*[[:alnum:]]+(\.[[:alnum:]]{3,4}|(\.[[:alnum:]]{2}){2})/', 'i')
Update: Improvements in 10g2
All of you, who are using 10g2 or XE (which includes some of 10g2 features) may want to take a look at several improvements in this version. First of all, there are new, perl influenced meta characters.
Rewriting my example from the first lesson, the WHERE clause would look like this:
WHERE NOT REGEXP_LIKE(t.col1, '^\d+$')Or my example with searching decimal numbers:
'^(\.\d+|\d+(\.\d*)?)$'Saves some space, doesn't it? However, this will only work in 10g2 and future releases.
Some of those meta characters even include non matching lists, for example "\S" is equivalent to "[^ ]", so my example in the second part could be changed to:
SELECT NVL(LENGTH(REGEXP_REPLACE('Having fun with regular expressions', '\S')), 0)
FROM dual
;Other meta characters support search patterns in strings with newline characters. Just take a look at the link I've included.
Another interesting meta character is "?" non-greedy. In 10g2, "?" not only means 0 or 1 occurrence, it means also the first occurrence. Let me illustrate with a simple example:
SELECT REGEXP_SUBSTR('Having fun with regular expressions', '^.* +')
FROM dual
;This is old style, "greedy" search pattern, returning everything until the last space.
SELECT REGEXP_SUBSTR('Having fun with regular expressions', '^.* +?')
FROM dual
;In 10g2, you'd get only "Having " because of the non-greedy search operation. Simulating that behavior in 10g1, I'd have to change the pattern to this:
SELECT REGEXP_SUBSTR('Having fun with regular expressions', '^[^ ]+ +')
FROM dual
;Another new option is the "x" match parameter. It's purpose is to ignore whitespaces in the searched string. This would prove useful in ignoring trailing/leading spaces for example. Checking on unsigned integers with leading/trailing spaces would look like this:
SELECT REGEXP_SUBSTR(' 123 ', '^[0-9]+$', 1, 1, 'x')
FROM dual
;However, I've to be careful. "x" would also allow " 1 2 3 " to qualify as valid string.
I hope you enjoyed reading this introduction and hope you'll have some fun with using regular expressions.
C.
Fixed some typos ...
Message was edited by:
cd
Included 10g2 features
Message was edited by:
cd

Can I write this condition with only one reg expr in Oracle (regexp_substr in my example)?I meant to use only regexp_substr in select clause and without regexp_like in where clause.
but for better understanding what I'd like to get
next example:
a have strings of two blocks separated by space.
in the first block 5 symbols of [01] in the second block 3 symbols of [01].
In the first block it is optional to meet one (!), in the second block it is optional to meet one (>).
The idea is to find such strings with only one reg expr using regexp_substr in the select clause, so if the string does not satisfy requirments should be passed out null in the result set.
with t as (select '10(!)010 10(>)1' num from dual union all
select '1112(!)0 111' from dual union all --incorrect because of '2'
select '(!)10010 011' from dual union all
select '10010(!) 101' from dual union all
select '10010 100(>)' from dual union all
select '13001 110' from dual union all -- incorrect because of '3'
select '100!01 100' from dual union all --incorrect because of ! without (!)
select '100(!)1(!)1 101' from dual union all -- incorrect because of two occurencies of (!)
select '1001(!)10 101' from dual union all --incorrect because of length of block1=6
select '1001(!)10 1011' from dual union all) --incorrect because of length of block2=4
select '10110 1(>)11(>)0' from dual union all)--incorrect because of two occurencies of (>)
select '1001(>)1 11(!)0' from dual)--incorrect because (!) and (>) are met not in their blocks
--end of test data

Inline display of error message for a regular expression validation

Hi All,
I am using ApexLib in my application.
I am using regular expression validation for some of the items.
Those validation will happen when the button is pressed and the message will be displayed as per the error.
But, I want the errors to be displayed immediately when the focus is away from that item.
as we do for required items.
could anybody help me to achieve it?
Thanks in advance
bye
Srikavi

Hi Srikavi,
to achieve a Validation of an item when leaving the field you'll have to use some javascript code (as ApexLib does internally).
What do you need:
- onChange - Event on your Item
- some Javascript code which is called in the onChange Event (you can put this code either in your page html header or, if it is used more often in your application, in a seperate js File)
- call the ApexLib method apexlib.error.showError to display your error
I actually never tried it myself, but i'm pretty sure that this will work (according to what i've seen in the ApexLib code).
Have fun and tell us how it went,
Peter
Edited by: peter_raganitsch on Sep 5, 2008 11:56 AM

Regular expression - get longest number from string

I believe it is easy one but I can't get it.Lets say I have a string 'A1_1000' I want to substract the 1000 using regular expression. When I feed Match regular expression I get '1' which is not the longest number. I know other ways of doing that but I want clean solution in one step. Does anybody knows the right regular expression to accomplish that? Thanks!
LV 2011, Win7
Solved!
Go to Solution.

ceties wrote:
This is the best solution I was able to come with. I am just wondering if there is "smoother way" without the cycle.
Since multiple checks are required I would tend to beieve that we do have to loop through the possibilities. in this example
I start check at offset "0" into the string for a number. Provided i find a number I check if it is longer that any previous number I found and if so save the new longer number in the shift register.
Have fun!
Ben
Message Edited by Ben on 04-15-2009 09:23 AM
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction
Attachments:
Find_Longest.PNG ‏33 KB

Regular expressions for URLs to match extensions

I am working on a simple method that will assign a specific extension
(e.g. ".jsp", ".php", ".cfm", etc.) to the end of a URL if it doesn't
find anything marking a valid extension, however, I do not want to add
an extension if one is found.
Consider my code:
import java.util.regex.Pattern;
public static final String urlEndSlashPattern = "/?";
public static final String urlQSPattern = "\\??([a-zA-Z0-9\\-_\\.]
+=[^&]*&?)*";
public static final String urlAnchorPattern = "#[^#]*$";
public static void addExtToUrl(String url, String myExt, String[]
exts) {
 StringBuffer sb = new StringBuffer();
 boolean hasExt = false;
 for (int i = 0; i < exts.length; i++) {
sb.append(".").append(exts).append(urlEndSlashPattern).append(urlQSPatte�rn).append(urlAnchorPattern);
if (Pattern.matches(sb.toString(), url)) {
hasExt = true;
sb = new StringBuffer();
if (!hasExt) {
url += "." + myExt;
The issue I want to bring up is the regular expression pattern I'm
using appears to fail. I want to check and see if the URL I provide
ends with a valid extension, followed by optional "/" or a query
string or an anchor or any combination of these.
Like say if I have
http://www.blah.com/index.html
Then don't add the ".jsp" extension
But if I have
http://www.blah.com/registration/
Then I *want* to add the ".jsp" extension:
http://www.blah.com/registration.jsp
Or if I have:
http://www.blah.com/registration/?foo=bar#baz
Then it needs to change to
http://www.blah.com/registration.jsp?foo=bar#baz
But if I have
http://www.blah.com/registration/index.php?foo=bar#baz
Then I do *not* add the ".jsp" extension.
Hope that makes sense now. Bottom line is that the pattern above
doesn't seem to work. Ideas?
Thanks

Ok, just for fun, let's try it.
URL: http://www.blah.com/?bar=baz#anchor
Absolutely valid URL and something possible (remember, Balus, this is from a database entry, thus, it can be anything at all!)
Let's split onto the last /
Your last entry will be
?bar=baz#anchor
So if I re-insert the .jsp that it would not find I get
http://www.blah.com/.jsp?bar=baz#anchor
INVALID URL
Now let's try this one, BalusC:
http://www.blah.com/index.jsp?forwardURL=http://www.wee.com/gotcha_balus/
Now we split according to the ... last /
http://www.blah.com/index.jsp?forwardURL=http://www.wee.com/gotcha_balus.jsp
Valid URL, but possibly wrong when the query string value for "forwardURL" is read, thus, making the URL ultimately wrong.
Two examples that show that splitting by the last / can't work here.

Regular Expression for match pattern

Hi guys, I need some help.
In one part of my test system, I give to the program a sequence of temperatures, which are numbers separated by a comma. Due to a possible error, the user can forget the coma, and the program gets unexpected values.
For example, "20, 70, -10" is a right value, whereas "20 70, -10" would be a wrong one.
Which regular expression will detect this comma absence?
Thanx in advance.

OK, makes it more difficult (and more fun )
My original version failed also when the space was forgotten. DOH!
Try this version. It get's complicated cause the scan from string likes ignoring spaces... So we change the spaces
Hope this helps
Shane.
PS The ideas given by others are still a better solution, but if you're stuck........
Using LV 6.1 and 8.2.1 on W2k (SP4) and WXP (SP2)
Attachments:
Check input string with commas(array).vi ‏39 KB

Open APEX Wiki needs a regular expression mastermind

Hello,
And I'm not talking about someone that kinda knows regular expression's, we need one of those sick in the head people that think regular expressions are fun to do on a Friday night :) for some of this wiki work.
If your interested please email me directly at [email protected]
Sorry for putting this out here but I'm throwing a wide net on this one and want to kickstart this application.
Carl

[Heh, the "not built here", "we can build it better" approach, the bane (and boon!) of all software development]
Seriously, I don't think Perl regexps are all that "non-standard" as compared to the POSIX standard. They certainly have some quirks w.r.t zero-length forward/backward assertions (?pattern) and they might have some more character classes [[:pattern:]] but on the whole it is the same stuff.
Yes, given that TWiki is built entirely in Perl, it might have more than its fair share of "Perl-isms" that might make converting to Oracle regexps untenable, but there is no reason to use the TWiki "dialect" of wiki-markup. There are tons of Wiki dialects around, Google for keywords like "wiki dialect markup convert html" finds lots of relevant hits (like the link I posted earlier).
All I am saying is that it might make sense to not reinvent the wheel especially for something as complicated as regular expressions.
References:
http://www.ayni.com/perldoc/perl5.8.0/pod/perlre.html
http://builder.com.com/5100-6388-5224420.html
http://www.oreilly.com/catalog/oracleregex/index.html
http://www.redwingnet.com/hioug/Presentations/Regular_Expressions/Oracle10gRegularExpressions.htm

Handling Regular expression ambiguitie s

Hi All,
I am attemting to make my own regular expression class. (Just for fun) :)
I have successfully converted the regular expression into a DFA ( deterministic finite automaton ). However, as i have noticed, there is still ambiguity in transition when it comes to certain classes of regular expressions such as a+[^0-9]+w. this means one or more a's followed by one or more symbols that are NOT numbers, followed by a w. Now if we have a string "aaaw", the first a is matched quite nicely, but should the second 'a' be treated as an a that is to be matched with "a+" or "[^0-9]" ??
Is there any algorithm that resloves such an ambiguity?
Any help would be much appreciated. I am stuck with this issue and don't seem to have any leads at all :)

Hi All,
My problem is now solved. I have refined the suggestions to come up with the following algorithm ( excuse the errors, and ineffeciencies, if any )
push all DFA states into a queue
while !(dfaStateQueue.empty())
       currentDFAState = dfaStateQueue.pop()
       push all transitions of currentDFAState to transitionQueue.
       store all transitions into transitionArray.
        while ( !transitionQueue.empty() )
               compareWithTransition = transitionQueue.pop();
               for(i = 1 to length(transitionArray) )
                      compareWithTransition = transitionArray;
Set intersec = set_intersection(compareWithTransition.getChars, compareToTransition.getChars);
if( !intersect.empty() )
//characters in compareWith but not in compareTo
Set minus1 = set_difference(compareWithTransition, compareToTransition)
//characters in compareTo but not in compareWith.
Set minus2 = set_difference(compareToTransition, compareWithTransition)
//compareWithTransition is subset of compareToTransition
if(minus1.empty())
replace characters of compareTo with characters in set minus2
replace characters of a closure transition of compareTo
with characters in set minus2
compareWithTransition.nextDfa.addAllTransitions
(compareToTransition.nextDfa.getTransitions())
continue
//compareToTransition is subset of compareWithTransition
else if(minus2.empty())
replace characters of compareWithTransition with characters in set minus1
replace characters of a closure transition of compareWithTransition
with characters in set minus2
compareToTransition.nextDfa.addAllTransitions
(compareWithTransition.nextDfa.getTransitions())
continue;
end if
create new DFA state D;
currentDFAState.addTransition(intersect, D);
push D onto queue.
D.addAllTransitions(compareWithTransition.nextDfa.getTransitions());
D.addAllTransitions(compareToTransition.nextDfa.getTransitions());
replace characters of compareWithTransition with characters in set minus1
replace characters of compareToTransition with characters in set minus2
end if
end for
end while
end while
I hope this helps everyone at large. Now there is no need for backtracking at all and DFAs are now truly "DFAs" :)
I dont know if other tools employ this technique or not. Please ignore the glaring ineffeciencies. I have give the algorithm the way i coded it ( Never considered myself as effecient programmer in the first place) HAHAHA
Chears,
AUTOMATON

Logical AND in Java Regular Expressions

I'm trying to implement logical AND using Java Regular Expressions.
I couldn't figure out how to do it after reading Java docs and textbooks. I can do something like "abc.*def", which means that I'm looking for strings which have "abc", then anything, then "def", but it is not "pure" logical AND - I will not find "def.*abc" this way.
Any ideas, how to do it ?
Baken

First off, looks like you're really talking about an "OR", not an "AND" - you want it to match abc.*def OR def.*abc right? If you tried to match abc.*def AND def.*abc nothing would ever match that, as no string can begin with both "abc" and "def", just like no numeric value can be both 2 and 5.
Anyway, maybe regex isn't the right tool for this job. Can you not simply programmatically match it yourself using String methods? You want it to match if the string "starts with" abc and "ends with" def, or vice-versa. Just write some simple code.

Help in Regular expression

Hello..
I wanted to write a regular expression to match the foll string..
 
 NEW ORLEANS, Louisiana (CNN) 
-- Two years after Hurricane Katrina devastated coastal areas of Louisiana and Mississippi, residents say much of America has forgotten their plight.
 
I tried doing..
Matcher matcher= Pattern.compile(" ([^<^>]+?)", Pattern.CASE_INSENSITIVE).matcher(story);
Its not working...
is there any other soln?

Theres probably a better way to do this but here's a way that works.
import java.util.regex.*;
public class RegexTester{
public static void main(String[] args){
 String text =
 " " +
 " NEW ORLEANS, Louisiana (CNN) " +
 "-- Two years after Hurricane Katrina devastated coastal areas of Louisiana and Mississippi," +
 "residents say much of America has forgotten their plight." +
 " ";
 String regex = ">((?:\\s*[\\S&&[^<>]]+\\s*)*?)<";
 Pattern p = Pattern.compile(regex);
 Matcher m = p.matcher(text);
 while(m.find()){
 System.out.println("Match: '" + m.group(1) + "'");
}

Help in regular expression matching

I have three expressions like
1) [(y2009)(y2011)]
2) [(y2008M5)(y2011M3)] or [(y2009M5)(y2010M12)]
3) [(y2009M1d20)(y2011M12d31)]
i want regular expression pattern for the above three expressions
I am using :
REGEXP_LIKE(timedomainexpression, '???[:digit:]{4}*[:digit:]{1,2}???[:digit:]{4}*[:digit:]{1,2}??', 'i');
but its giving results for all above expressions while i want different expression for each.
i hav used * after [:digit:]{4}, when i am using ? or . then its giving no results. Please help in this situation ASAP.
Thanks

I dont get your question Can you post your desired output? and also give some sample data.
Please consider the following when you post a question.
1. New features keep coming in every oracle version so please provide Your Oracle DB Version to get the best possible answer.
You can use the following query and do a copy past of the output.
select * from v$version 2. This forum has a very good Search Feature. Please use that before posting your question. Because for most of the questions
that are asked the answer is already there.
3. We dont know your DB structure or How your Data is. So you need to let us know. The best way would be to give some sample data like this.
I have the following table called sales
with sales
as
 select 1 sales_id, 1 prod_id, 1001 inv_num, 120 qty from dual
 union all
 select 2 sales_id, 1 prod_id, 1002 inv_num, 25 qty from dual
select *
from sales 4. Rather than telling what you want in words its more easier when you give your expected output.
For example in the above sales table, I want to know the total quantity and number of invoice for each product.
The output should look like this
Prod_id sum_qty count_inv
1 145 2 5. When ever you get an error message post the entire error message. With the Error Number, The message and the Line number.
6. Next thing is a very important thing to remember. Please post only well formatted code. Unformatted code is very hard to read.
Your code format gets lost when you post it in the Oracle Forum. So in order to preserve it you need to
use the {noformat}{noformat} tags.
The usage of the tag is like this.
<place your code here>\
7. If you are posting a *Performance Related Question*. Please read
 {thread:id=501834} and {thread:id=863295}.
 Following those guide will be very helpful.
8. Please keep in mind that this is a public forum. Here No question is URGENT.
 So use of words like *URGENT* or *ASAP* (As Soon As Possible) are considered to be rude.

Regular expression alphabets

Hi
I want to retrieve the data if the data contains a character or a space or '-' thru select query .
Please help me in writing the combination of 3 with regular expression.
Thanks!!

VT wrote:
Hi,
Try this
SELECT *
FROM <TABLE> WHERE REGEXP_LIKE(<COLUMN>, '[a-z -][A-Z -]');cheers
VTThat won't work as it's expecting at least two characters with the first having to be a-z (lower case) or space or "-" followed by A-Z (upper case) or space or "-".
The correct way is either:
[a-zA-Z -]or
[[:alpha:] -]using the alpha set is often preferable as it can work differently with different character sets/languages rather than restricting to just the a-zA-Z ranges.
Generating a reference for your own database characterset/language can be useful...
SQL> select level-1 as asc_code, decode(chr(level-1), regexp_substr(chr(level-1), '[[:print:]]'), CHR(level-1)) as chr,
2 decode(chr(level-1), regexp_substr(chr(level-1), '[[:graph:]]'), 1) is_graph,
3 decode(chr(level-1), regexp_substr(chr(level-1), '[[:blank:]]'), 1) is_blank,
4 decode(chr(level-1), regexp_substr(chr(level-1), '[[:alnum:]]'), 1) is_alnum,
5 decode(chr(level-1), regexp_substr(chr(level-1), '[[:alpha:]]'), 1) is_alpha,
6 decode(chr(level-1), regexp_substr(chr(level-1), '[[:digit:]]'), 1) is_digit,
7 decode(chr(level-1), regexp_substr(chr(level-1), '[[:cntrl:]]'), 1) is_cntrl,
8 decode(chr(level-1), regexp_substr(chr(level-1), '[[:lower:]]'), 1) is_lower,
9 decode(chr(level-1), regexp_substr(chr(level-1), '[[:upper:]]'), 1) is_upper,
10 decode(chr(level-1), regexp_substr(chr(level-1), '[[:print:]]'), 1) is_print,
11 decode(chr(level-1), regexp_substr(chr(level-1), '[[:punct:]]'), 1) is_punct,
12 decode(chr(level-1), regexp_substr(chr(level-1), '[[:space:]]'), 1) is_space,
13 decode(chr(level-1), regexp_substr(chr(level-1), '[[:xdigit:]]'), 1) is_xdigit
14 from dual
15 connect by level <= 256
16 /
ASC_CODE C IS_GRAPH IS_BLANK IS_ALNUM IS_ALPHA IS_DIGIT IS_CNTRL IS_LOWER IS_UPPER IS_PRINT IS_PUNCT IS_SPACE IS_XDIGIT
 0 1
 1 1
 2 1
 3 1
 4 1
 5 1
 6 1
 7 1
 8 1
 9 1 1
 10 1 1
 11 1 1
 12 1 1
 13 1 1
 14 1
 15 1
 16 1
 17 1
 18 1
 19 1
 20 1
 21 1
 22 1
 23 1
 24 1
 25 1
 26 1
 27 1
 28 1
 29 1
 30 1
 31 1
 32 1 1 1
 33 ! 1 1 1
 34 " 1 1 1
 35 # 1 1 1
 36 $ 1 1 1
 37 % 1 1 1
 38 & 1 1 1
 39 ' 1 1 1
 40 ( 1 1 1
 41 ) 1 1 1
 42 * 1 1 1
 43 + 1 1 1
 44 , 1 1 1
 45 - 1 1 1
 46 . 1 1 1
 47 / 1 1 1
 48 0 1 1 1 1 1
 49 1 1 1 1 1 1
 50 2 1 1 1 1 1
 51 3 1 1 1 1 1
 52 4 1 1 1 1 1
 53 5 1 1 1 1 1
 54 6 1 1 1 1 1
 55 7 1 1 1 1 1
 56 8 1 1 1 1 1
 57 9 1 1 1 1 1
 58 : 1 1 1
 59 ; 1 1 1
 60 < 1 1 1
 61 = 1 1 1
 62 > 1 1 1
 63 ? 1 1 1
 64 @ 1 1 1
 65 A 1 1 1 1 1 1
 66 B 1 1 1 1 1 1
 67 C 1 1 1 1 1 1
 68 D 1 1 1 1 1 1
 69 E 1 1 1 1 1 1
 70 F 1 1 1 1 1 1
 71 G 1 1 1 1 1
 72 H 1 1 1 1 1
 73 I 1 1 1 1 1
 74 J 1 1 1 1 1
 75 K 1 1 1 1 1
 76 L 1 1 1 1 1
 77 M 1 1 1 1 1
 78 N 1 1 1 1 1
 79 O 1 1 1 1 1
 80 P 1 1 1 1 1
 81 Q 1 1 1 1 1
 82 R 1 1 1 1 1
 83 S 1 1 1 1 1
 84 T 1 1 1 1 1
 85 U 1 1 1 1 1
 86 V 1 1 1 1 1
 87 W 1 1 1 1 1
 88 X 1 1 1 1 1
 89 Y 1 1 1 1 1
 90 Z 1 1 1 1 1
 91 [ 1 1 1
 92 \ 1 1 1
 93 ] 1 1 1
 94 ^ 1 1 1
 95 _ 1 1 1
 96 ` 1 1 1
 97 a 1 1 1 1 1 1
 98 b 1 1 1 1 1 1
 99 c 1 1 1 1 1 1
 100 d 1 1 1 1 1 1
 101 e 1 1 1 1 1 1
 102 f 1 1 1 1 1 1
 103 g 1 1 1 1 1
 104 h 1 1 1 1 1
 105 i 1 1 1 1 1
 106 j 1 1 1 1 1
 107 k 1 1 1 1 1
 108 l 1 1 1 1 1
 109 m 1 1 1 1 1
 110 n 1 1 1 1 1
 111 o 1 1 1 1 1
 112 p 1 1 1 1 1
 113 q 1 1 1 1 1
 114 r 1 1 1 1 1
 115 s 1 1 1 1 1
 116 t 1 1 1 1 1
 117 u 1 1 1 1 1
 118 v 1 1 1 1 1
 119 w 1 1 1 1 1
 120 x 1 1 1 1 1
 121 y 1 1 1 1 1
 122 z 1 1 1 1 1
 123 { 1 1 1
 124 | 1 1 1
 125 } 1 1 1
 126 ~ 1 1 1
 127 1
 128 Ç 1 1 1
etc.
{code}

Help in query using regular expression

HI,
I need a help to get the below output using regular expression query. Please help me.
SELECT REGEXP_SUBSTR ('PWRPKG(P/W+P/L+CC)', '[^+]+', 1, lvl) val, lvl
FROM DUAL,(SELECT LEVEL lvl FROM DUAL
CONNECT BY LEVEL <=(SELECT MAX ( LENGTH ('PWRPKG(P/W+P/L+CC)') - LENGTH (REPLACE ('PWRPKG(P/W+P/L+CC)','+',NULL))+ 1) FROM DUAL));
I need the output as
correct result:
==============
val lvl
P/W 1
P/L 2
CC 3
But i tried the above it is not coming the above result. Please help me where i did a mistake.
Thanks in advance

Frank gave you a solution in your other thread. You could simplify it if you are on 11g:
SQL> select * from table_x
2 /
TXT
TECHPKG(INTELLI CC+FRT SONAR)
PWRPKG(P/W+P/L+CC)
select txt,
 regexp_substr(
 txt,
 '(.*\()*([^+)]+)',
 1,
 column_value,
 null,
 2
 ) element,
 column_value element_number
from table_x,
 table(
 cast(
 multiset(
 select level
 from dual
 connect by level <= regexp_count(txt,'\+') + 1
 as sys.OdciNumberList
order by rowid,
 column_value
TXT ELEMENT ELEMENT_NUMBER
TECHPKG(INTELLI CC+FRT SONAR) INTELLI CC 1
TECHPKG(INTELLI CC+FRT SONAR) FRT SONAR 2
PWRPKG(P/W+P/L+CC) P/W 1
PWRPKG(P/W+P/L+CC) P/L 2
PWRPKG(P/W+P/L+CC) CC 3
SQL> SY.

Fun fun regular expressions

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