UPDATE profile SET
favourties=CONCAT(favourties,"123")
WHERE id=1
i want to append 123 in favourties but if default value of favourties is set to NULL then this query will not work. What will be query if favourties is set to NULL and then append 123 with it
UPDATE profile SET favourties=CONCAT(IFNULL(favourties, ''),"123") WHERE id=1
Wrap the field around with the COALESCE function:
UPDATE profile
SET favourties = CONCAT(COALESCE(favourties, ''),"123")
WHERE id=1
You probably can't concatenate something to NULL. Maybe you can use coalesce?
UPDATE profile SET favourties=CONCAT(COALESCE(favourites,""),"123") WHERE id=1
see: http://dev.mysql.com/doc/refman/5.0/en/comparison-operators.html#function_coalesce
You can use ifnull like #zerkms says, but that is not in the SQL standard. It is a tiny tad faster though. Read up on it at this link: http://sqlblog.com/blogs/adam_machanic/archive/2006/07/12/performance-isnull-vs-coalesce.aspx
You can also use CONCAT_WS() (docs) which deals with NULLs as you would expect: converts them to an empty string:
UPDATE profile SET favourties = CONCAT_WS('', favourties, "123") WHERE id = 1;
I personally actually only use CONCAT_WS() now because having to worry about NULLs annoys me. I rarely use NULLs so I don't have to worry about it, but just incase. It's just an annoying thing to figure out why you you're ending up with an empty string when it just doesn't seem to make sense.
In PHP, I use:
SET `trans`=concat('$var', trans)
to add to a string already in the trans column.
It wouldn't work on column named group without using back ticked group inside the brackets as well, whereas with trans, back ticks were not needed.
Related
so I'm currently working on a MySQL trigger. I'm trying to assign values to two variables when a new record is inserted. Below are the queries:
SET mssgDocNo = (SELECT Document_ID FROM CORE_MSSG WHERE Message_ID = new.MSSG_ID);
SET mssgRegime = (SELECT CONCAT (Regime_Type, Regime_Code) FROM T_DOC WHERE CD_Message_ID = new.MSSG_ID);;
For some reason, the second SQL query is not picking up the 'new.MSSG_ID' condition while the first query in same trigger recognizes it. I really can't figure out what seems to be the problem.
When I replace the 'new.MSSG_ID' with a hard-coded value from the database in the second query it seems to work. I doubt the 'new.MSSG_ID' is the problem because it works perfectly fine in the first query.
I've tried pretty much anything I could think of. Would appreciate the help.
I would write these more simply as:
SELECT mssgDocNo := Document_ID
FROM CORE_MSSG
WHERE Message_ID = new.MSSG_ID;
SELECT mssgRegime := CONCAT(Regime_Type, Regime_Code)
FROM T_DOC
WHERE CD_Message_ID = new.MSSG_ID;
The SET is not necessary.
I did make one other change that might make it work. I removed the space after CONCAT. Some versions of MySQL have trouble parsing spaces after function calls.
So I have a bunch of users in a column that get refreshed as:
Bill#test.comXYZ
Tom#test.comXYZ
John#test.comXYZ
We refresh the database each week and I need to update these appropriate emails to:
Bill#domain.com
Tom#domain.com
John#domain.com
I figured I can use concat to do the latter, but I am stuck on the former issue. Is there a way to split the values (like split Bill#test.comXYZ into Bill - #test.comXYZ and then remove the #TEXT values?).
Anyways, any help will be much appreciated.
You can use the mySQL replace function, i.e.
UPDATE mytable
set myfield = replace (myfield, '#test.comXYZ', 'domain.com')
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_replace
Okay, not quite sure how to explain it but I'll try my best...
I want to run a MySQL query to set names to 'Unmanaged Team [id]'
My thoughts were initially to use the following (but it doesn't work as hoped).
mysql_query("UPDATE `table` SET `field`='Unmanaged Team'+`id`");
I've tried some variations of that, but I can't quite seems to figure it out, and I don't want to do them one by one, as that would just use far too many queries for something I'm sure can be done in 1.
Many thanks for taking some time to help me out :)
You can use concat:
update `table` set `field` = concat('Unmanaged Team', id);
concat_ws (concat with separator) is also useful if you want whitespace (or some other separator).
Use
SET field = CONCAT('something ',somefield)
I need to change the information in a column to Degraded, where it is Feature Broken or Degradated. Is this the correct line?
UPDATE tablename
SET column = 'Degraded'
WHERE column = 'Degradated' OR column= 'Feature Broken'
Thanks
You may want to use an IN operator, to avoid the OR:
UPDATE tablename SET columnname = 'Degraded' WHERE columnname IN ('Degradated', 'Feature Broken');
Also, I would suggest running a SELECT first so you are somewhat aware of how many rows will be changed with your command.
Yes, it is.
You could make it more concise (but it is exactly the same otherwise)
...
WHERE column IN ('Degradated','Feature Broken')
I have in my db strings like www.domain.com and http://www.domain.com. I want to prepend to all entries the http:// but not affect other urls and as a result have this: http://http://www.domain.com
Can this be done with mysql only? I have used REPLACE(field,'www','http://www'), but this replaces also the http://www with http://http://www
Thanks in advance
EDIT
I forgot to mention that in the field there might be entries which don't contain www or http://www and therefore I don't want to alter or maybe there are entries like <p>domain</p> in which CONCAT() prepends the http:// before <p>
Try adding a WHERE clause to your update to only update fields that do not already have 'http://'. Test it out like this
SELECT CONCAT('http://', field) FROM foo WHERE LOCATE('http://', field)=0
and your UPDATE syntax would be:
UPDATE foo SET field=CONCAT('http://',field) WHERE LOCATE('http://', field)=0
I won't worry about performance as this seems like a one-off kind of script. That said, you can couple LEFT and CONCAT to achieve this:
UPDATE mytable
SET mycolumn = CONCAT('http://',mycolumn)
WHERE LEFT(mycolumn,7) <> 'http://'
Do note that I'm not taking CapItaliZation in to account. You may also want to consider sanitizing the information either before adding it to the database, or maybe make a trigger to do it for you.
Search and Replace Query - mysql replace
Here is the SQL query to replace string in your MySQL database table:
UPDATE table_name SET column_name = REPLACE(column_name,'original_string','replace_string')
Here is what I did to change the path URLs in all my previous posts.
UPDATE `wp_posts` SET `post_content` = REPLACE(`post_content`,'http://localhost/','https://sureshkamal1.wordpress.com/')