Replace Non alpha numeric characters with empty string MYSQL - mysql

select
file,
REPLACE(FILE, '[:alnum:]'+'.'+,'') AS Collection
FROM
CollectionData;
select
file,
REPLACE(FILENAME, '^[a-zA-Z0-9\.]','') AS Collection
FROM collectiondata;
I would like to replace all the non alpha numeric characters from the string including .file extensions from the string as given below.
AXS00003600.txt to AXS
NXS4DG00003600.txt to NXS4DG
I am not able to replace the non alpha numeric data when I execute the above query. What could be the problem?

Unfortunately, MySQL contains no REGEXP_REPLACE operation. The ordinary REPLACE you're trying to use doesn't work with regular expressions. You'll need to do this in client code or maybe in a stored procedure.

Related

How can I trim Schema/Database Name in MySQL

An Application I am using is passing schema name as a string literal and it is getting single quoted and generating MySQL Syntax error:
'somedatabasename'
I want to trim the single quotes and use the schema name to form my query.
SELECT field FROM somedatabasename.sometable
I can only use a single Query and cannot use Stored Procedure (I know using stored functions I can manipulate the strings.)
Is there a way in MySQL where I can Use TRIM or REPLACE with the FROM keyword.

MySQL find/replace with a unique string inside

not sure how far I'm going to get with this, but I'm going through a database removing certain bits and pieces in preparation for a conversion to different software.
I'm struggling with the image tags as on the site they currently look like
[img:<string>]<image url>[/img:<string>]
those strings are in another field called bbcode_uid
The query I'm running to make the changes so far is
UPDATE phpbb_posts SET post_text = REPLACE(post_text, '[img:]', '');
So my actual question, is there any way of pulling in each string from bbcode_uid inside of that SQL query so that I don't have to run the same command 10,000+ times, changing the unique string every time.
Alternatively could I include something inside [img:] to also include the next 8 characters, whatever they may be, as that is the length of the string that is used.
Hoping to save time with this, otherwise I might have to think of another way of doing it.
As requested.
The text I wish to replace would be
[img:1nynnywx]http://i.imgur.com/Tgfrd3x.jpg[/img:1nynnywx]
I want to end up with just
http://i.imgur.com/Tgfrd3x.jpg
Just removing the code around the URL, however each post_text has a different string which is contained inside bbcode_uid.
Method 1
LIB_MYSQLUDF_PREG
If you want more regular expression power in your database, you can consider using LIB_MYSQLUDF_PREG. This is an open source library of MySQL user functions that imports the PCRE library. LIB_MYSQLUDF_PREG is delivered in source code form only. To use it, you'll need to be able to compile it and install it into your MySQL server. Installing this library does not change MySQL's built-in regex support in any way. It merely makes the following additional functions available:
PREG_CAPTURE extracts a regex match from a string. PREG_POSITION returns the position at which a regular expression matches a string. PREG_REPLACE performs a search-and-replace on a string. PREG_RLIKE tests whether a regex matches a string.
All these functions take a regular expression as their first parameter. This regular expression must be formatted like a Perl regular expression operator. E.g. to test if regex matches the subject case insensitively, you'd use the MySQL code PREG_RLIKE('/regex/i', subject). This is similar to PHP's preg functions, which also require the extra // delimiters for regular expressions inside the PHP string
you can refer this link :github.com/hholzgra/mysql-udf-regexp
Method 2
Use php program, fetch records one by one , use php preg_replace
refer : www.php.net/preg_replace
reference:http://www.online-ebooks.info/article/MySql_Regular_Expression_Replace.html
You might be able to do this with substring_index().
The following will work on your example:
select substring_index(substring_index(post_text, '[/img:', 1), ']', -1)

MySQL for replace with wildcard

I'm trying to write a SQL update to replace a specific xml node with a new string:
UPDATE table
SET Configuration = REPLACE(Configuration,
"<tag>%%ANY_VALUE%%</tag>"
"<tag>NEW_DATA</tag>");
So that
<root><tag>SDADAS</tag></root>
becomes
<root><tag>NEW_DATA</tag></root>
Is there a syntax im missing for this type of request?
Update: MySQL 8.0 has a function REGEX_REPLACE().
Below is my answer from 2014, which still applies to any version of MySQL before 8.0:
REPLACE() does not have any support for wildcards, patterns, regular expressions, etc. REPLACE() only replaces one constant string for another constant string.
You could try something complex, to pick out the leading part of the string and the trailing part of the string:
UPDATE table
SET Configuration = CONCAT(
SUBSTR(Configuration, 1, LOCATE('<tag>', Configuration)+4),
NEW_DATA,
SUBSTR(Configuration, LOCATE('</tag>', Configuration)
)
But this doesn't work for cases when you have multiple occurrences of <tag>.
You may have to fetch the row back into an application, perform string replacement using your favorite language, and post the row back. In other words, a three-step process for each row.

MySQL: Getting a value from a string using a regex?

One column returns such values:
Something";s:5:"value";s:3:"900";s:11:"print_
I want to extract all numbers that are at least 3 digits long, in the above case thats 900. How can I do that in MySQL? Maybe using a regex? I cant use any index, the length of the string and the number in the string can be different.
Thanks!
Try unserialize() it if you are using PHP! And then var_dump it to see the strings and arrays
You can't extract them using MySQL, use any other language for that.
What you can do is include a Where Clause, that will make the work easier for your script.
Assuming your column is called "serialized" in the table "example"
SELECT serialized FROM example WHERE serialized REGEXP '[0-9]{3,}'
Please note that REGEXP is just outputting 1 or 0
After you did the query, use the regex functions of your language do extract the numbers like so:
([0-9]{3,})*

Using REGEX to alter field data in a mysql query

I have two databases, both containing phone numbers. I need to find all instances of duplicate phone numbers, but the formats of database 1 vary wildly from the format of database 2.
I'd like to strip out all non-digit characters and just compare the two 10-digit strings to determine if it's a duplicate, something like:
SELECT b.phone as barPhone, sp.phone as SPPhone FROM bars b JOIN single_platform_bars sp ON sp.phone.REGEX = b.phone.REGEX
Is such a thing even possible in a mysql query? If so, how do I go about accomplishing this?
EDIT: Looks like it is, in fact, a thing you can do! Hooray! The following query returned exactly what I needed:
SELECT b.phone, b.id, sp.phone, sp.id
FROM bars b JOIN single_platform_bars sp ON REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(b.phone,' ',''),'-',''),'(',''),')',''),'.','') = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(sp.phone,' ',''),'-',''),'(',''),')',''),'.','')
MySQL doesn't support returning the "match" of a regular expression. The MySQL REGEXP function returns a 1 or 0, depending on whether an expression matched a regular expression test or not.
You can use the REPLACE function to replace a specific character, and you can nest those. But it would be unwieldy for all "non-digit" characters. If you want to remove spaces, dashes, open and close parens e.g.
REPLACE(REPLACE(REPLACE(REPLACE(sp.phone,' ',''),'-',''),'(',''),')','')
One approach is to create user defined function to return just the digits from a string. But if you don't want to create a user defined function...
This can be done in native MySQL. This approach is a bit unwieldy, but it is workable for strings of "reasonable" length.
SELECT CONCAT(IF(SUBSTR(sp.phone,1,1) REGEXP '^[0-9]$',SUBSTR(sp.phone,1,1),'')
,IF(SUBSTR(sp.phone,2,1) REGEXP '^[0-9]$',SUBSTR(sp.phone,2,1),'')
,IF(SUBSTR(sp.phone,3,1) REGEXP '^[0-9]$',SUBSTR(sp.phone,3,1),'')
,IF(SUBSTR(sp.phone,4,1) REGEXP '^[0-9]$',SUBSTR(sp.phone,4,1),'')
,IF(SUBSTR(sp.phone,5,1) REGEXP '^[0-9]$',SUBSTR(sp.phone,5,1),'')
) AS phone_digits
FROM sp
To unpack that a bit... we extract a single character from the first position in the string, check if it's a digit, if it is a digit, we return the character, otherwise we return an empty string. We repeat this for the second, third, etc. characters in the string. We concatenate all of the returned characters and empty strings back into a single string.
Obviously, the expression above is checking only the first five characters of the string, you would need to extend this, basically adding a line for each position you want to check...
And unwieldy expressions like this can be included in a predicate (in a WHERE clause). (I've just shown it in the SELECT list for convenience.)
MySQL doesn't support such string operations natively. You will either need to use a UDF like this, or else create a stored function that iterates over a string parameter concatenating to its return value every digit that it encounters.