I'm trying to write a function that removes any occurrence of any of the 26 alphabet letters from a string.
In: 'AA123A' -> Out: '123'
In: 'AB-123-CD% -> Out: '-123-%'
All I can find on Google is how to remove non-numeric characters, which all seem to be formed around defining the numbers you want to keep. But I want to keep any symbols too.
The 'simple' answer is 26 nested REPLACE for each letter, but I can't believe there isn't a better way to do it.
I could define a string of A-Z and loop through each character, calling the REPLACE 26 times - makes the code simpler but is the same functionally.
Does anyone have an elegant solution?
If I understand correctly, you can use TRANSLATE, e.g.:
SELECT REPLACE(TRANSLATE('AB-123- CDdcba%', 'ABCDabcd',' '), ' ', '');
SELECT REPLACE(TRANSLATE('AB-123- CDdcba%', 'ABCDabcd','AAAAAAAA'), 'A', '');
first case trimming also spaces,
second one, preserving existing spaces.
Just add the rest of characters to 'ABCDabcd' argument and keep 'AAAAAAAA' same length as the second argument.
Related
I have two types of URL's which I would need to clean, they look like this:
["//xxx.com/se/something?SE_{ifmobile:MB}{ifnotmobile:DT}_A_B_C_D_E_F_G_H"]
["//www.xxx.com/se/car?p_color_car=White?SE_{ifmobile:MB}{ifnotmobile:DT}_A_B_C_D_E_F_G_H"]
The outcome I want is;
SE_{ifmobile:MB}{ifnotmobile:DT}_A_B_C_D_E_F_G_H"
I want to remove the brackets and everything up to SE, the URLS differ so I want to remove:
First URL
["//xxx.com/se/something?
Second URL:
["//www.xxx.com/se/car?p_color_car=White?
I can't get my head around it,I've tried this .*\/ . But it will still keep strings I don't want such as:
(1 url) =
something?
(2 url) car?p_color_car=White?
You can use
regexp_replace(FinalUrls, r'.*\?|"\]$', '')
See the regex demo
Details
.*\? - any zero or more chars other than line breakchars, as many as possible and then ? char
| - or
"\]$ - a "] substring at the end of the string.
Mind the regexp_replace syntax, you can't omit the replacement argument, see reference:
REGEXP_REPLACE(value, regexp, replacement)
Returns a STRING where all substrings of value that match regular
expression regexp are replaced with replacement.
You can use backslashed-escaped digits (\1 to \9) within the
replacement argument to insert text matching the corresponding
parenthesized group in the regexp pattern. Use \0 to refer to the
entire matching text.
Hi may i know what does the below query means?
REGEXP_REPLACE(number,'[^'' ''-/0-9:-#A-Z''[''-`a-z{-~]', 'xy') ext_number
part 1
In terms of explaining what the function function call is doing:
It is a function call to analyse an input string 'number' with a regex (2nd argument) and replace any parts of the string which match a specific string. As for the name after the parenthesis I am not sure, but the documentation for the function is here
part 2
Sorry to be writing a question within an answer here but I cannot respond in comments yet (not enough rep)
Does this regex work? Unless sql uses different syntax this would appear to be a non-functional regex. There are some red flags, e.g:
The entire regex is wrapped in square parenthesis, indicating a set of characters but seems to predominantly hold an expression
There is a range indicator between a single quote and a character (invalid range: if a dash was required in the match it should be escaped with a '\' (backslash))
One set of square brackets is never closed
After some minor tweaks this regex is valid syntax:
^'' ''\-\/0-9:-#A-Z''[''-a-z{-~]`, but does not match anything I can think of, it is important to know what string is being examined/what the context is for the program in order to identify what the regex might be attempting to do
It seems like it is meant to replaces all ASCII control characters in the column or variable number with xy.
[] encloses a class of characters. Any character in that class matches. [^] negates that, hence all characters match, that are not in the class.
- is a range operator, e.g. a-z means all characters from a to z, like abc...xyz.
It seams like characters enclosed in ' should be escaped (The second ' is to escape the ' in the string itself.) At least this would make some sense. (But for none of the DBMS I found having a regexp_replace() function (Postgres, Oracle, DB2, MariaDB, MySQL), I found something in the docs, that would indicate this escape mechanism. They all use \, but maybe I missed something? Unfortunately you didn't tag which DBMS you're actually using!)
Now if you take an ASCII table you'll see, that the ranges in the expression make up all printable characters (counting space as printable) in groups from space to /, 0 to 9, : to #, etc.. Actually it might have been shorter to express it as '' ''-~, space to ~.
Given the negation, all these don't match. The ones left are from NUL to US and DEL. These match and get replaced by xy one by one.
In my database I should only have data written using Polish alphabet but sometimes there are symbols not included in Polish alphabet (words copied from source with different encoding) that correspond to Polish letters in another encoding. Is it possible to somehow convert symbols outside of Polish alphabet to corresponding letters?
The only solution I figured is to manually find and replace those characters but maybe you have better solution to my problem.
Question concerns Oracle SQL Language.
I don't have database in front of me but as I remember correctly the example could look like this - two rows from my db:
ŚWIAT
ÚWIAT
and what I need is to convert Ú that doesn't belong to Polish alphabet to Ś.
You can try this. Experiment with it first to see if it works.
If I want to change every occurrence of the letter z with a j in a string, I would use the translate function: translate(text_string, 'z', 'j'). I don't have to use the letters z and j; instead, I can write translate(text_string, chr(122), chr(106) - to find out the character code, I use select ascii('z') from dual;. For example:
SQL> select translate('banzo', chr(122), chr(106)) from dual;
TRANS
-----
banjo
This changes every occurrence of z to j in text_string.
Now, you will have to find the code for the characters you want to change (both the "from" and the "to" characters) in your character set - it should be your session character set, not the database character set. (At least I think this is correct; experiment with it or read the documentation for CHR and perhaps for TRANSLATE - CHR returns the character code in the DATABASE character set unless you indicate otherwise, while I believe TRANSLATE uses the session character set.)
The function ascii may or may not work for non-ASCII characters, but if you google the name of your character set, you should find a character set table that will show you the codes for all the letters available in that character set.
Then, if this works, you can do the translation in one shot - translate(text_string, 'abcd', 'qrst') will change every 'a' to a 'q', every 'b' to an 'r' etc. And with chr(...), instead of 'abcd' you can write chr(97) || chr(98) || chr(99) || chr(100).
I need to use SQL to find a sequence of characters at a specific position in a string.
Example:
atcgggatgccatg
I need to find 'atg' starting at character 7 or at character 7-9, either way would work. I don't want to find the 'atg' at the end of the string. I know about LIKE but couldn't find how to use it for a specific position.
Thank you
In MS Access, you could write this as:
where col like '???????atg*' or
col like '????????atg*' or
col like '?????????atg*'
However, if you interested in this type of comparison, you might consider using a database that supports regular expressions.
If you have a look at this page you'll find that LIKE is entirely capable of doing what you want. To find something at, for example, a 3 char offset you can use something like this
SELECT * FROM SomeTable WHERE [InterestingField] LIKE '___FOO%'
The '_' (underscore) is a place marker for any char. Having 3 "any char" markers in the pattern, with a trailing '%', means that the above SQL will match anything with FOO starting from the fourth char, and then anything else (including nothing).
To look for something 7 chars in, use 7 underscores.
Let me know ifthis isn't quite clear.
EDIT: I quoted SQL Server stuff, not Access. Swap in '?' where I have '_', use '*' instead of '%', and check out this link instead.
Revised query:
SELECT * FROM SomeTable WHERE [InterestingField] LIKE '???FOO*'
From within an Oracle 11g database, using SQL, I need to remove the following sequence of special characters from a string, i.e.
~!##$%^&*()_+=\{}[]:”;’<,>./?
If any of these characters exist within a string, except for these two characters, which I DO NOT want removed, i.e.: "|" and "-" then I would like them completely removed.
For example:
From: 'ABC(D E+FGH?/IJK LMN~OP' To: 'ABCD EFGHIJK LMNOP' after removal of special characters.
I have tried this small test which works for this sample, i.e:
select regexp_replace('abc+de)fg','\+|\)') from dual
but is there a better means of using my sequence of special characters above without doing this string pattern of '\+|\)' for every special character using Oracle SQL?
You can replace anything other than letters and space with empty string
[^a-zA-Z ]
here is online demo
As per below comments
I still need to keep the following two special characters within my string, i.e. "|" and "-".
Just exclude more
[^a-zA-Z|-]
Note: hyphen - should be in the starting or ending or escaped like \- because it has special meaning in the Character class to define a range.
For more info read about Character Classes or Character Sets
Consider using this regex replacement instead:
REGEXP_REPLACE('abc+de)fg', '[~!##$%^&*()_+=\\{}[\]:”;’<,>.\/?]', '')
The replacement will match any character from your list.
Here is a regex demo!
The regex to match your sequence of special characters is:
[]~!##$%^&*()_+=\{}[:”;’<,>./?]+
I feel you still missed to escape all regex-special characters.
To achieve that, go iteratively:
build a test-tring and start to build up your regex-string character by character to see if it removes what you expect to be removed.
If the latest character does not work you have to escape it.
That should do the trick.
SELECT TRANSLATE('~!##$%sdv^&*()_+=\dsv{}[]:”;’<,>dsvsdd./?', '~!##$%^&*()_+=\{}[]:”;’<,>./?',' ')
FROM dual;
result:
TRANSLATE
-------------
sdvdsvdsvsdd
SQL> select translate('abc+de#fg-hq!m', 'a+-#!', etc.) from dual;
TRANSLATE(
----------
abcdefghqm