I've got a field in my table for tags on some content, separated by spaces, and at the moment I'm using:
SELECT * FROM content WHERE tags LIKE '%$selectedtag%'"
But if the selected tag is elephant, it will select content tagged with bigelephant and elephantblah etc...
How do I get it to just select what I want precisely?
SELECT * FROM content WHERE tags RLIKE '[[:<:]]elephant[[:>:]]'
If your table is MyISAM, you can use this:
SELECT * FROM content WHERE MATCH(tags) AGAINST ('+elephant' IN BOOLEAN MODE)
, which can be drastically improved by creating a FULLTEXT index on it:
CREATE FULLTEXT INDEX ix_content_tags ON content (tags)
, but will work even without the index.
For this to work, you should adjust ##ft_min_wold_len to index tags less than 4 characters long if you have any.
You could use MySQL's regular expressions.
SELECT * FROM content WHERE tags REGEXP '(^| )selectedtag($| )'
Be aware, though, that the use of regular expressions adds an overhead and might perform poorly in some circumstances.
Another simple way, if you can alter your database data, is to ensure that there is an empty space before the first tag and after the last one; A little like: " elephant animal ". That way you can use wildcards.
SELECT * FROM content WHERE tags LIKE '% selectedtag %'
I would consider a different design here. This constitutes a many-to-many relationship, so you could have a tags table and a join table. In general, atomicity of data saves you from a lot of headaches.
An added bonus of this approach is that you can rename a tag without having to edit every entry containing that tag.
A: You have to create a separate tags table which points to the content with contentid and contains a keyword, then:
select a.*
from content a,tags b
where a.id=b.contentid
group by a.id;
B: Put a comma between the tags and befor and afther them, like ",bigelephant,elephant,", then use like "%,elephant,%"
WHERE tags LIKE '% '{$selectedtag}' %'
OR tags LIKE ''{$selectedtag}' %'
OR tags LIKE '% '{$selectedtag}''
The '%' is a wildcard in SQl. Remove the wildcards, and you will get precisely what you ask for.
Redo the table design but for now if you use spaces to delimit between tags you COULD do this:
SELECT * FROM content WHERE tags LIKE '% elephant %';
Just make sure that you lead and end with a space as well (or replace the spaces with commas if you're doing it that way)
Again though, the best option is to set up a many-to-many relationship in your database but I suspect you're looking for a quick and dirty one-off fix.
Related
I store lyrics of songs and also allow chords to be added by putting them between square brackets (e.g: [Dm7]). Here's an example of lyrics stored in my database:
Left my fear [Dm7]by the side of the [B]road
Hear You[C] speak won't let[E] go
Fall to my knees
...
What I want to do is search for lyrics in songs. For example I might want to search for the lyrics fear by the side . The problem is the [Dm7] in my example above does not allow a simple LIKE search.
Is it possible to do a search (REGEX?) that excludes text such as [Dm7] from a query? If so how? Please note that the chords between the square brackets can vary.
You might like to consider a fulltext index, and then use match() against() in your where clause. Example:
create fulltext index ftx on songs(lyrics);
select *
from songs
where match(lyrics) against('fear by the side');
demo here
The matching is a little fuzzy, and you can't use the boolean mode matching because the chords don't have whitespace on both sides, but the normal mode should be sufficient.
The 'fuzziness' of the match can be used to provide a match ranking - works best on english language, which this seems to be. For example:
select match(lyrics) against('fear by the side') rank,
lyrics from songs
where match(lyrics) against('fear by the side')
order by match(lyrics) against('fear by the side') desc;
Would sort the results by best match, and also return the matching rank.
updated demo
The fulltext index also has a boolean mode, which as the same suggests, can be used to force the results to include or exclude certain words like so:
match(column) against('+word -otherword' in boolean mode) would return all rows for which column contains word but does not have otherword.
your fulltext index can also be multi column, if you desire.
Thanks to #SvenB and his suggestion of this post, this was my answer.
REPLACE(col, SUBSTRING(col, (LOCATE('[', col)), LOCATE(']', col) - (LOCATE('[', col)) + 1), '') LIKE '%fear by the side%'
It's a bit messy but works! I think in the long term FULL TEXT search is the way to go based on others comments.
I'm trying to return all rows where some column contains all keywords. Keywords can be in any order and surrounded by anything. I've looked into FULL TEXT searches but none seem to give the kind of control I want. I can do something like this:
SELECT *
FROM articles
WHERE body LIKE '%term1%' AND body LIKE '%term2%' AND body LIKE '%term3'...
But this gets messy with an arbitrary number of search terms. Is there a better way of doing this?
Have a look at Fulltext binary search (on that page search for A Basic Boolean Searching Application).
Try this
SELECT * FROM `articles` WHERE MATCH (body) AGAINST
('term1 +term2 +term3 etc...' IN BOOLEAN MODE)
here '+[keyword]' is the equivalent of AND. if you search a keyword in different columns, so you can; where match (col1,col2,col3 etc...) against ('keyword'). Remember, you need to define a FULLTEXT index that contains which columns will be searched (used in "match (col1,col2...)" part)
I am working on a project.I have a paragraph and I have some tags like C#,mysql,.net,ajax etc.I want to check whether my paragraph contains these tags or not and if it contains which one it contains and how many tags matches.Depending on the number of tags matched I have to give a score.I am not getting how to do this i can't use in clause here neither i can use find_in_set().Please help me how should I achieve this.
You might want to look at the REGEXP feature of mysql:
CREATE TABLE texts (
paragraph text,
FULLTEXT INDEX( paragraph ))
engine = myisam;
INSERT INTO texts ( paragraph ) values
( "this is a very uninteresting paragraph "),
( "MySQL can be fun and useful, with or without PHP!"),
(" I have misspelled phpone, but I didn't mean the programming language!");
select paragraph FROM texts
where paragraph REGEXP( "[[:<:]]php[[:>:]]");
It's not as efficient as a FULLTEXT search but may better fit your needs. Depends.
MySQL's Full text search seems to be exactly what you're looking for, although by default it might have some troubles searching for C#, because of both the short length and the special character.
Alternatively, you can just use LIKE, to search for paragraph LIKE '%PHP%'.
i'm making a searcher for my site and this works fine with one word querys
$consulta = mysql_query("SELECT * FROM recetas WHERE (titulo LIKE '%$busqueda%' OR intro LIKE '%$busqueda%' OR extra LIKE '%$busqueda%') ORDER BY id DESC");
But if i type 'two words' it doesn't give me result, $busqueda it's result from a <input/> given through $_POST['TERM']
any idea what i'm missing?
SOLVED
i was missing to encode the variable to URI... oops haha THANKS!
Think of how your query will look at the end:
Select ... where '%two words%. ...
If you want to search for words like that, you'll have to massage the data to look more like:
... Like '%two%words%'
... Like '%two%' or like '%words%'
depending on your exact search requirements
Unless the two words are adjacent in the text, the LIKE operator won't find them. You may want to use full text search.
In order to find two non-contiguous words, the input would need to be split up into two separate values and the query would have to look something like this:
WHERE (titulo LIKE '%$word1%' OR intro LIKE '%$word1%' OR extra LIKE '%$word1%' OR
titulo LIKE '%$word2%' OR intro LIKE '%$word2%' OR extra LIKE '%$word2%' )
That is assuming you want a match with either word. If both must match, then something like this:
WHERE (titulo LIKE '%$word1%' AND titulo like '%$word2%' OR
intro LIKE '%$word1%' AND intro LIKE '%$word2%' OR
extra LIKE '%$word1%' AND extra LIKE '%$word2%' )
And one other thing. It would be better to use parameterized queries to avoid an SQL injection.
where ( MATCH( titulo, intro, extra) AGAINST ('word1 word2' in BOOLEAN MODE))
I currently have a table for products with it's own set of tags and a table for news with it's own set of tags. I wanted to add related news to the products page so I was thinking of using like but since the column tags in the products page is something like
(Products) tags- manutd, man utd, football
(news) tags - manutd, blah, bruha [this one is related]
(news) tags - man, utd, bruha [this one is not related]
I wanted to use a query to show all news containing any of the tags(from products) seperated by commas using mysql. How should I go about constructing such a query? If there is a better way of doing this a little explanation would be helpful too. Thanks
Do you have the product tags at hand or do you want to join the two tables based on their tag similarity? In the first case, I would try something like this:
select ...
from News n
where n.tags REGEXP 'manutd|man utd|football'
Note that I used the product tag string you provided above, replaced the commas by | and removed the whitespace to the left and right of the commas.