i'd like to update a table field in my mysql data base and convert all links to lowercase, e.g.
to convert:
http://www.domamain.com/MyLinks/News/FileName.html
to
http://www.domamain.com/mylinks/news/filename.html
Can this be done?
Thanks
You can convert an entire column to lowercase with the LOWER() function
UPDATE mytable
SET url = LOWER(url)
It seems that you can't do regular expression replace in MYSQL though:
How to do a regular expression replace in MySQL?
Related
I have a table named testlink and it has url and newtarget columns.
I would like to take the string expressions https://domain1.com/ here in the url column and change all the data in the newtarget column to https://domain1.com/search/?q= pulled string expression.
So briefly;
url columns from https://domain1.com/topic1
will be changed to https://domain1.com/search/?q=topic1 in the newtarget column
There are about 6 thousand different topics (lines) available.
Database: Mysql / Phpmyadmin.
use REPLACE
UPDATE testlink
SET newtarget = REPLACE(url,'https://domain1.com/','https://domain1.com/search/?q=')
MySQL REPLACE() replaces all the occurrences of a substring within a
string.
REPLACE(str, find_string, replace_with)
If you want to conditionally change the value, you can use string manipulations:
update t
set url = concat(left(url, length(url) - length(substring_index(url, '/', -1))), 'q=', substring_index(url, '/', -1))
where url like 'https://domain1.com/%';
This uses substring_index() to get the last part of the string (after the last /). It uses left() to get the first part (based on the length of the last part) and then concatenates the values you want.
Of course, test this logic using a SELECT before implementing an UPDATE.
If you're using MySQL 8, then you'd be able to do that with REGEXP_REPLACE.
For your example, this should work :
SELECT REGEXP_REPLACE('https://domain1.com/topic1','(https:\/\/domain1\.com\/)(.+)','$1search/?q=$2')
Is it possible to search and replace with a regex expression in MySQL?
I have a thousand values on a column containing a JSON string, somewhere inside each JSON are several occurrences of a string that I have to change.
I've already made a PHP script that do the job, but it is a little slow.
Is there a nicer way to do that using only MySQL?
Something like:
UPDATE mytable SET value = "disabled" WHERE data REGEXP '{"field": "(.+)"}'
MariaDB has REGEXP_REPLACE(), which might provide the tool you need.
I'am trying to write a SELECT-Statement to retrieve a list of Usernames from my Database. My Pattern is: /placeholder\d+/ig and I already tested it and can confirm it is working properly. I'am trying to retrieve every Placeholder in the Table.
I also tried to escape the \ after placeholder.
My SQL-Statement is: SELECT * FROM table WHERE (name REGEX '/placeholder\d+/ig') ... I tried different variations with backticks, etc or LIKE instead of REGEXbut LIKEonly has % and _ as a Wildcard.
Does my RegEx pattern needs to be modified in order to work with MySQL?
Unlike most scripting languages, MySQL is not using the PREG library for regular expression matching.
So yes, you need to modify your regex to make it work properly in MySQL:
SELECT * FROM table WHERE name REGEXP 'placeholder[0-9]+'
OR
SELECT * FROM table WHERE name REGEXP 'placeholder[[:digit:]]+'
There are no short-hand character classes like \d in MySQL. Also, you do not use the regex-delimeter ("/../si" is just ".." in MySQL)
Read the documentation on regular expressions in MySQL for more information.
I have one table emp in MySQL database having column as name. In that name column, the value is 'abc\xyz'. I want to search this value. I have tried using following query:
select * from emp where name like 'abc\xyz';
Also i have tried
select * from emp where name like 'abc\xyz' escape '\\';
But i did not found any output. Could you please help me in finding such strings? Such strings can have special character at any location.
Thanks in advance.
You may try like this:
select * from emp
where empname like '%abc\\\\xyz%'
SQL Fiddle Demo
From the docs:
Because MySQL uses C escape syntax in strings (for example, “\n” to represent a newline character), you must double any “\” that you use in LIKE strings. For example, to search for “\n”, specify it as “\\n”. To search for “\”, specify it as “\\\\”; this is because the backslashes are stripped once by the parser and again when the pattern match is made, leaving a single backslash to be matched against.
SELECT REPLACE(text,'\\','') FROM tbl
You can use REPLACE to remove some special chars :)
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.