Remove unwanted characters from starting position - oracle

I need to remove only characters at the beginning.
GFG2014JP34343
D2013GH43422
HHH2014JP34343
CC2013GH43422
Output:
2014JP34343
2013GH43422
2014JP34343
2013GH43422
I tried REGEXP with different pattern.

We can use a regex replacement here:
SELECT val, REGEXP_REPLACE(val, '^[^[:digit:]]+', '') AS val_out
FROM yourTable;

Related

Regex to select all the commas from string that do not have any white space around them

I want to select all the commas in a string that do not have any white space around. Suppose I have this string:
"He,she, They"
I want to select only the comma between he and she. I tried this in rubular and came up with this regex:
(,[^(,\s)(\s,)])
This selects the comma that I want, but also selects an s which is a character after it.
In your regex (,[^(,\s)(\s,)]) you capture a comma followed by a negated character class that matches not any of the specified characters, which could also be written as (,[^)(,\s]) which will capture for example ,s in a group,
What you could do is use a positive lookahead and a positve lookbehind to check what is on the left and what is on the right is not a \S whitespace character:
(?<=\S),(?=\S)
Regex demo
In Ruby, you may use [[:space:]] to match any (Unicode) whitespace and [^[:space:]] to match any char other than whitespace. Using these character classes inside lookarounds solves the problem:
/(?<=[^[:space:]]),(?=[^[:space:]])/
See the Rubular demo
Here,
(?<=[^[:space:]]) - a positive lookbehind that matches a location that is immediately preceded with a non-whitespace char (if the string start position should also be matched, replace with (?<![[:space:]]))
, - a comma
(?=[^[:space:]]) - a positive lookahead that matches a location that is immediately followed with a non-whitespace char (if the string end position should also be matched, replace with (?![[:space:]])).
Check the regex below and use the code hope it will help you!
re = /[^\s](,)[^\s]/m
str = 'check ,my,domain, qwe,sd'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Check LIVE DEMO HERE

Special character Oracle REGEXP

I need to allow only set of characters i.e.,
a to z A to Z 0 to 9 . !##$% *()_=+|[]{}"'';:?/.,-
but When I add dash(-) character to below query it is not working please help me at earliest.
SELECT :p_string FROM dual
WHERE NOT REGEXP_LIKE (translate(:p_string,chr(10)||chr(11)||chr(13), ' '),'[^]^A-Z^a-z^0-9^[^.^{^}^!^#^#^$^%^*^(^)^_^=^+^|^\^{^}^"^''^;^:^?^/^,^-^ ]' );
[.-.] will work fine on this query .
The extra ^ symbols inside the bracket expression in your pattern are not, as I think you expect, negations; only the first ^ inside the brackets does that.
The main issue that is causing, apart from allowing that actual circumflex symbol to be matched when you didn't seem to want it, is that you end up with ^-^ being treated as a range.
To include a literal - it has to be the first or last thing in the brackets; from the docs:
To specify a right bracket (]) in the bracket expression, place it first in the list (after the initial circumflex (^), if any).
To specify a hyphen in the bracket expression, place it first in the list (after the initial circumflex (^), if any), last in the list, or as an ending range point in a range expression.
So as you need to do both, make the hyphen last; you can change your pattern to:
'[^]A-Za-z0-9[.{}!##$%*()_=+|\{}"'';:?/, -]'
You could also skip the tralsnate step by including those special characters in the pattern too:
'[^]A-Za-z0-9[.{}!##$%*()_=+|\{}"'';:?/, '||chr(10)||chr(11)||chr(13)||'-]'
Looks like you need to permit only (7-bit) ASCII characters with exception of ~ and ^
In this case I would try it like this:
WHERE CONVERT(p_string, 'US7ASCII') = p_string
AND NOT REGEXP_LIKE(p_string, '~|\^')
Instead of CONVERT(p_string, 'US7ASCII') = p_string you can also use ASCIISTR(REPLACE(p_string, '\', '/')) = REPLACE(p_string, '\', '/')

String gsub - Replace characters between two elements, but leave surrounding elements

Suppose I have the following string:
mystring = "start/abc123/end"
How can you splice out the abc123 with something else, while leaving the "/start/" and "/end" elements intact?
I had the following to match for the pattern, but it replaces the entire string. I was hoping to just have it replace the abc123 with 123abc.
mystring.gsub(/start\/(.*)\/end/,"123abc") #=> "123abc"
Edit: The characters between the start & end elements can be any combination of alphanumeric characters, I changed my example to reflect this.
You can do it using this character class : [^\/] (all that is not a slash) and lookarounds
mystring.gsub(/(?<=start\/)[^\/]+(?=\/end)/,"7")
For your example, you could perhaps use:
mystring.gsub(/\/(.*?)\//,"/7/")
This will match the two slashes between the string you're replacing and putting them back in the substitution.
Alternatively, you could capture the pieces of the string you want to keep and interpolate them around your replacement, this turns out to be much more readable than lookaheads/lookbehinds:
irb(main):010:0> mystring.gsub(/(start)\/.*\/(end)/, "\\1/7/\\2")
=> "start/7/end"
\\1 and \\2 here refer to the numbered captures inside of your regular expression.
The problem is that you're replacing the entire matched string, "start/8/end", with "7". You need to include the matched characters you want to persist:
mystring.gsub(/start\/(.*)\/end/, "start/7/end")
Alternatively, just match the digits:
mystring.gsub(/\d+/, "7")
You can do this by grouping the start and end elements in the regular expression and then referring to these groups in in the substitution string:
mystring.gsub(/(?<start>start\/).*(?<end>\/end)/, "\\<start>7\\<end>")

Ruby Regex Match Between "foo" and "bar"

I have unfortunately wandered into a situation where I need regex using Ruby. Basically I want to match this string after the underscore and before the first parentheses. So the end result would be 'table salt'.
_____ table salt (1) [F]
As usual I tried to fight this battle on my own and with rubular.com. I got the first part
^_____ (Match the beginning of the string with underscores ).
Then I got bolder,
^_____(.*?) ( Do the first part of the match, then give me any amount of words and letters after it )
Regex had had enough and put an end to that nonsense and crapped out. So I was wondering if anyone on stackoverflow knew or would have any hints on how to say my goal to the Ruby Regex parser.
EDIT: Thanks everyone, this is the pattern I ended up using after creating it with rubular.
ingredientNameRegex = /^_+([^(]*)/;
Everything got better once I took a deep breath, and thought about what I was trying to say.
str = "_____ table salt (1) [F]"
p str[ /_{3}\s(.+?)\s+\(/, 1 ]
#=> "table salt"
That says:
Find at least three underscores
and a whitespace character (\s)
and then one or more (+) of any character (.), but as little as possible (?), up until you find
one or more whitespace characters,
and then a literal (
The parens in the middle save that bit, and the 1 pulls it out.
Try this: ^[_]+([^(]*)\(
It will match lines starting with one or more underscores followed by anything not equal to an opening bracket: http://rubular.com/r/vthpGpVr4y
Here's working regex:
str = "_____ table salt (1) [F]"
match = str.match(/_([^_]+?)\(/)
p match[1].strip # => "table salt"
You could use
^_____\s*([^(]+?)\s*\(
^_____ match the underscore from the beginning of string
\s* matches any whitespace character
( grouping start
[^(]+ matches all non ( character at least once
? matches the shortest possible string (non greedy)
) grouping end
\s* matches any whitespace character
\( find the (
"_____ table salt (1) [F]".gsub(/[_]\s(.+)\s\(/, ' >>>\1<<< ')
# => "____ >>>table salt<<< 1) [F]"
It seems to me the simplest regex to do what you want is:
/^_____ ([\w\s]+) /
That says:
leading underscores, space, then capture any combination of word chars or spaces, then another space.

how to remove leading and trailing non-alphabetic characters in ruby

I want to remove any leading and trailing non-alphabetic character in my string.
for eg. ":----- pt-br:-" , i want "pt-br"
Thanks
result = subject.gsub(/\A[\d_\W]+|[\d_\W]+\Z/, '')
will remove non-letters from the start and end of the string.
\A and \Z anchor the regex at the start/end of the string (^/$ would also match after/before a newline which is probably not what you want - but that might not matter in this case);
[\d_\W]+ matches one or more digits, the underscore or anything else that is not an alphanumeric character, leaving only letters.
| is the alternation operator.
In ruby 1.9.1 :
":----- pt-br:-".partition( /[a-zA-Z](...)[a-zA-Z]/ )[1]
partition searches the pattern in the string and returns the part before it, the match, and the part after it.
result = subject.gsub(/^[^a-zA-Z]+/, '').gsub(/[^a-zA-Z]+$/, '')

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