I am struggling with this query and want to know if I am wasting my time and need to write a php script or is something like the following actually possible?
UPDATE my_table
SET #userid = user_id
AND SET filename('http://pathto/newfilename_'#userid'.jpg')
FROM my_table
WHERE filename
LIKE '%_%' AND filename
LIKE '%jpg'AND filename
NOT LIKE 'http%';
Basically I have 700 odd files that need renaming in the database as they do not match the filenames as I am changing system, they are called in the database.
The format is 2_gfhgfhf.jpg which translates to userid_randomjumble.jpg
But not all files in the database are in this format only about 700 out of thousands. So I want to identify names that contain _ but don't contain http (thats the correct format that I don't want to touch).
I can do that fine but now comes the tricky bit!!
I want to replace that file name userid_randomjumble.jpg with http://pathto/filename_userid.jpg So I want to set the column user_id in that row to a variable and insert it into my new filename.
The above doesn't work for obvious reasons but I am not sure if there is a way round what I'm trying to do. I have no idea if it's possible? Am I wasting my time with this and should I turn to PHP with mysql and stop being lazy? Or is there a way to get this to work?
Yes it is possible without the php. Here is a simple example
SET #a:=0;
SELECT * FROM table WHERE field_name = #a;
Yes you can do it using straightforward SQL:
UPDATE my_table
SET filename = CONCAT('http://pathto/newfilename_', userid, '.jpg')
WHERE filename LIKE '%\_%jpg'
AND filename NOT LIKE 'http%';
Notes:
No need for variables. Any columns of rows being updated may be referenced
In mysql, use CONCAT() to add text values together
With LIKE, an underscore (_) has a special meaning - it means "any single character". If you want to match a literal underscore, you must escape it with a backslash (\)
Your two LIKE predicates may be safely merged into one for a simpler query
Related
Using MySQLAdmin. Moved data from Windows server and trying to replace case in urls but not finding the matches. Need slashes as I don't want to replace text in anything but the urls (in post table). I think the %20 are the problem somwhow?
UPDATE table_name SET field = replace(field, '/user%20name/', '/User%20Name/')
The actual string is more like:
https://www.example.com/forum/uploads/user%20name/GFCI%20Stds%20Rev%202006%20.pdf
In a case you are using MariaDB you have REGEXP_REPLACE() function.
But best approach is to dump the table into the file. Open it in a Notepad ++
and run regex replace like specified on a pic:
Pattern is: (https:[\/\w\s\.]+uploads/)(\w+)\%20(\w+)((\/.*)+)
Replace with: $1\u$2\%20\u$3$4
Then import the table again
Hope this help
If its MariaDB, you can do the following:
UPDATE table_name SET field = REGEXP_REPLACE(field, '\/user%20name\/', '\/User%20Name\/');
First, please check, what is actually stored in the database: %20 is a html-entity which represents a whitespace. Usually, when you are storing this inside the database, it will be represented as an actual whitespace (converted before you store it) -> Hence your replace doesn't match the actual data.
The second option that might be possible - depending on what you want to do: You are seeing the URL containing %20, therefore you created your database records (which you would like to fetch) with that additional %20 - And when you now try to query your results based on the actual url, the %20 is replaced with an "actual" whitespace (before your query) and hence it doesn't match your stored data.
In my database I have a table called 'content' and a field called 'link' and there are almost 300,000 records in that table.
In the field called 'link' there are a number of records that look like this :
http://www.example.com/blah/blah/123456789/url=http://www.destination.com
Unfortunately the prefix part of the records are individually unique where the numbered portion is constant changing from 90 to 150 alpha-numeric characters
I would like to remove the prefix up to and/or including the url=
So that the only thing left in the record is :
http://www.destination.com OR
I could even work with
url=http://www.destination.com
and simply do a replace command against the "url=" part as a second mysql command.
If there was a wildcard command, this job would be much easier and I would just wildcard everything showing up in the link record between :
http://www.example.com/blah/blah/ wildcard url=
But as everyone knows... there is no such wildcard available
So it had me looking at the UPDATE, SET and TRIM(LEADING commands
UPDATE content
SET link =
TRIM(LEADING 'url=' FROM link)
But this DID NOT generate the changes I wanted
And so I took the labor intensive method of downloading the database and using a Search and Replace program to make the changes to the 44 thousand records that contained these parameters.
But I would love to find a command that I could simply pass to the database to make this simpler in the future.
Any thoughts on how to accomplish this change in the future would be greatly appreciated.
Thanks in advance ;
You can use the SUBSTRING_INDEX function:
UPDATE content SET link=SUBSTRING_INDEX( `link` , 'url=', -1 )
I have not tested it, so I would recommend you check that substring_index returns the desired string first.
Assuming that the part you want to keep always begins with 'http://' you could get the desired result string with the help of the SUBSTRING_INDEX function:
SELECT CONCAT('http://', SUBSTRING_INDEX(link, 'http://', -1)) FROM content;
and fix your table with the simple statement
UPDATE
content
SET
link = CONCAT('http://', SUBSTRING_INDEX(link, 'http://', -1));
Explanation:
SUBSTRING_INDEX with third parameter negative returns the substring from the last occurence of the needle in the second parameter to the end. Because 'http://' isn't included in the return value, we add it again.
Remark:
If you've got https:// urls too, you should be able to adapt my solution.
I have a bunch of image references in a table like:
data/fabrics/signature/signature1.jpg
data/fabrics/signature/signature2.jpg
And I need to go through the table and add an additional folder to the image path like:
data/group1/fabrics/signature/signature1.jpg
data/group1/fabrics/signature/signature2.jpg
Is there any way to do this with just MySQL queries, or will I need to use PHP to concatenate the strings and then update the database?
You could use a simple replacement function, replacing the beginning of the string with a different beginning. Probably the easiest solution if the replacements are so simple.
UPDATE tbl SET col=REPLACE(col, 'data/fabrics', 'data/group1/fabrics') WHERE xxx;
You might have to run several of these, depending on the specific replacements needed, with different WHERE clauses.
update table1
set link=substring(link,1,charindex('/',link,1))+
'group1'+substring(link,charindex('/',link,1),LEN(link))
where (your condition)
SQL Fiddle
I have a table "locales" with a column named "name". The records in name always begin with a number of characters folowed by an underscore (ie "foo_", "bar_"...). The record can have more then one underscore and the pattern before the underscore may be repeated (ie "foo_bar_", "foo_foo_").
How, with a simple query, can I get rid of everything before the first underscore including the first underscore itself?
I know how to do this in PHP, but I cannot understand how to do it in MySQL.
SELECT LOCATE('_', 'foo_bar_') ... will give you the location of the first underscore and SUBSTR('foo_bar_', LOCATE('_', 'foo_bar_')) will give you the substring starting from the first underscore. If you want to get rid of that one, too, increment the locate-value by one.
If you now want to replace the values in the tables itself, you can do this with an update-statement like UPDATE table SET column = SUBSTR(column, LOCATE('_', column)).
select substring('foo_bar_text' from locate('_','foo_bar_text'))
MySQL REGEXs can only match data, they can't do replacements. You'd need to do the replacing client-side in your PHP script, or use standard string operations in MySQL to do the changes.
UPDATE sometable SET somefield=RIGHT(LENGTH(somefield) - LOCATE('_', somefield));
Probably got some off-by-one errors in there, but that's the basic way of going about it.
I found a CSV database of Cities/ZIP/GPS, and when I imported it, it added a " infront of the columns.
alt text http://www.grabup.com/uploads/58754a865eebd94c9aafaf7444b52d15.png?direct
I don't want to go in for 33,000 entries and do this manually, is there a query I can run that will remove the quotes?
i'm not a MySql expert but this should work: (based on my similar experience in Sql Server)
UPDATE table_name SET col_name = REPLACE(col_name, '"', '')
For more info on the REPLACE and other string parsing functions, see here:
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_replace
in sql server you coud do:
update mytable set state= substring(state,2,29)
change the "29" to whatever the actual length is.
I am sure mysql must have equivalent syntax.
Repeat for each field, it looks like there is only a handful of them.
As an alternative you could filter the original csv document - isn't that easier?