Using phpmyadmin and mysql I need to select records containing the string '&pageid=page' in order to replace it with a null string.
I tried
SELECT * FROM `wp_posts` where post_content like '%&pageid=page%'
but no record was selected.
I tried again with without the & like explained below
SELECT * FROM `wp_posts` where post_content like '%pageid=page%'
and it worked, so I had some records selected. At this point, I suppose that the '&' char must be handled in a different way. Any idea to solve this?
Use keyword escape to mention escape character for the query.
select stuff from mytab
where
mycol like '%\_to\_%' escape '\';
Related
I'm trying to select all rows that contain only alphanumeric characters in MySQL using:
SELECT * FROM table WHERE column REGEXP '[A-Za-z0-9]';
However, it's returning all rows, regardless of the fact that they contain non-alphanumeric characters.
Try this code:
SELECT * FROM table WHERE column REGEXP '^[A-Za-z0-9]+$'
This makes sure that all characters match.
Your statement matches any string that contains a letter or digit anywhere, even if it contains other non-alphanumeric characters. Try this:
SELECT * FROM table WHERE column REGEXP '^[A-Za-z0-9]+$';
^ and $ require the entire string to match rather than just any portion of it, and + looks for 1 or more alphanumberic characters.
You could also use a named character class if you prefer:
SELECT * FROM table WHERE column REGEXP '^[[:alnum:]]+$';
Try this:
REGEXP '^[a-z0-9]+$'
As regexp is not case sensitive except for binary fields.
There is also this:
select m from table where not regexp_like(m, '^[0-9]\d+$')
which selects the rows that contains characters from the column you want (which is m in the example but you can change).
Most of the combinations don't work properly in Oracle platforms but this does. Sharing for future reference.
Try this
select count(*) from table where cast(col as double) is null;
Change the REGEXP to Like
SELECT * FROM table_name WHERE column_name like '%[^a-zA-Z0-9]%'
this one works fine
I've been to the regexp page on the MySQL website and am having trouble getting the query right. I have a list of links and I want to find invalid links that do not contain a period. Here's my code that doesn't work:
select * from `links` where (url REGEXP '[^\\.]')
It's returning all rows in the entire database. I just want it to show me the rows where 'url' doesn't contain a period. Thanks for your help!
SELECT c1 FROM t1 WHERE c1 NOT LIKE '%.%'
Your regexp matches anything that contains a character that isn't a period. So if it contains foo.bar, the regexp matches the f and succeeds. You can do:
WHERE url REGEXP '^[^.]*$'
The anchors and repetition operator make this check that every character is not a period. Or you can do:
WHERE LOCATE(url, '.') = 0
BTW, you don't need to escape . when it's inside [] in a regexp.
Using regexp seems like an overkill here. A simple like operator would do the trick:
SELECT * FROM `links` WHERE url NOT LIKE '%.%
EDIT:
Having said that, if you really want to negate regexp, just use not regexp:
SELECT * FROM `links` WHERE url NOT REGEXP '[\\.]';
I need a SELECT query in MYSQL that will retrieve all rows in one table witch field values contain "?" char with one condition: the char is not the last character
Example:
ID Field
1 123??see
2 12?
3 45??78??
Returning rows would then be those from ID 1 and 3 that match the condition given
The only statement I have is:
SELECT *
FROM table
WHERE Field LIKE '%?%'
But, the MySQL query does not solve my problem..
The LIKE expressions also support a wildcard "_" which matches exactly one character.
So you can write an expression like the example below, and know that your "?" will not be the last character in the string. There must be at least one more character.
WHERE intrebare LIKE '%?_%'
Re comment from #JohnRuddell,
Yes, that's true, this will match the string "??" because a "?" exists in a position that is not the last character.
It depends whether the OP means for that to be a match or not. The OP says the string "45??78??" is a match, but it's not clear if they would intend that "4578??" to be a match.
An alternative is to use a regular expression, but this is a little more tricky because you have to escape a literal "?", so it won't be interpreted as a regexp metacharacter. Then also escape the escape character.
WHERE intrebare REGEXP '\\?[^?]'
you can just add an additional where where the last character is not a ?
SELECT *
FROM intrebari
WHERE intrebare LIKE '%?%' AND intrebare NOT LIKE '%?'
you could also do it like this
SELECT *
FROM intrebari
WHERE intrebare LIKE '%?%' AND RIGHT(intrebare,1) <> '?'
DEMO
Please help me resolve my query when using query - I just want to subtract a few characters and then use the % to find the matching LIKE:
select * from `providers` WHERE `name` LIKE SUBSTR('telin',1,4)%
Please let me know what i'm doing wrong, any kind of help is greatly appreciated!
Assuming telin is a column name rather than the literal string, it should be quoted in backticks. If it is the literal string, then there is obviously no need to extract a substring from it. I suspect however, that it was the result of a PHP variable you pasted here after echoing out the full query, then it is correctly single-quoted.
Anyway, you will need to concatenate the SUBSTR() result onto the '%' via CONCAT():
SELECT * FROM `providers` WHERE `name` LIKE CONCAT(SUBSTR(`telin`,1,4), '%');
But better would be to use LEFT() to compare the first 4 characters of each:
SELECT * FROM `providers` WHERE LEFT(`name`, 4) = LEFT(`telin`,4);
I am currently using the follow query:
SELECT *
FROM `wp_usermeta`
WHERE meta_key='avatar'
AND meta_key NOT LIKE '% '
ORDER BY RAND()
LIMIT 4
In that way, I want to try to get only field values, where no empty spaces re in the file name. Where is the error in my query? It still selects filenames with empty spaces in the filename.
Try
NOT LIKE '% %'
Your current wildcard match only catches trailing spaces.
Also, you're using meta_key twice. Should the column used in your LIKE clause be meta_value (or whatever it is in Wordpress).
This question is probably worth reading if you're concerned about performance - Which is faster — INSTR or LIKE?