I'm using MATCH AGAINST to search against multiple fields in the database, but am having trouble with the results.
The query is:
MATCH(productname, stockcode, productdescription, additional_1, additional_2, additional_3, additional_4, additional_5, additional_6, additional_7, additional_8) AGAINST ('red* tile*' IN BOOLEAN mode)
From the query, I would like both "red%" or "tile%" results, but this is returning records where the word 'requiRED' is included, which I don't want.
Can this be done?
Most probably, you have ft_min_word_len set to default value of 4.
red does not get indexed or matched in this setup and just ignored in the queries.
Change ft_min_word_len to a lesser value if you want to match red (requires rebuilding the index if you have one).
See this fiddle.
Update:
If you want both words matched, use this:
AGAINST ('+red* +tile*' IN BOOLEAN mode)
Related
So I'm having some difficulty creating exact searches in MySQL fulltext.
In my database, I'm trying to find jobs with a specific keyword in its title.
So I might try
WHERE MATCH(jobTitle) AGAINST ('"fs sales"' IN BOOLEAN MODE)
However, this finds matches on "sales", not "fs sales"
How can I ensure that "fs sales" matches EXACTLY on "fs sales" and not "sales"?
Table is InnoDB for reference.
"fs" is probably excluded from the search as too short.
Check the value of innodb_ft_min_token_size and manual: https://dev.mysql.com/doc/refman/5.6/en/fulltext-fine-tuning.html
You have to rebuild the index after changing that variable.
Your query should work. My guess, though is that you did not change the minimum word length, so "fs" was never indexed. See here for information on this.
Other possibilities are that there are other characters in the text, perhaps characters you do not see.
You might try this
select t.*
from (select . . .
WHERE MATCH(jobTitle) AGAINST ('+fs +sales' IN BOOLEAN MODE)
) t
where jobTitle like '%fs sales%';
This only does the like on the returned set from the match.
However, my best guess is that innodb_ft_min_token_size is set to its default value of 3, so "fs" is not being indexed.
you can do it like
select col1, col2 from table_name where text_column like '%fs sales%'
this will return all the records having fs sales in them..
I have a query like below:
SELECT prd_id FROM products WHERE MATCH (prd_search_field)
AGAINST ('+gul* +yetistiren* +adam*' in boolean mode);
This doesn't return the rows including 'gul'.
http://dev.mysql.com/doc/refman/5.0/en/fulltext-boolean.html
The document says this.
Then a search for '+word +the*' will likely return fewer rows than a
search for '+word +the':
The former query remains as is and requires both word and the* (a word starting with the) to be present in the document.
The latter query is transformed to +word (requiring only word to be present). the is both too short and a stopword, and either condition is enough to cause it to be ignored.
So as I understood the too short word condition must not be applied in my situation since I use * after each word. What's wrong with this?
As a solution I use the below query but since it's slow, I need to find another solution. Any idea would be appreciated? Thanks in advance..
SELECT prd_id FROM products WHERE 1 AND MATCH (prd_search_field)
AGAINST ('+yetistiren* +adam*' in boolean mode) AND prd_search_field
LIKE '%gul%';
As a note ft_min_word_length=4 as default in all shared hosting environments, and I cannot change it.
I'm pretty new to MySQL full-text searches and I ran into this problem today:
My company table has a record with "e-magazine AG" in the name column. I have a full-text index on the name column.
When I execute this query the record is not found:
SELECT id, name FROM company WHERE MATCH(name) AGAINST('+"e-magazi"*' IN BOOLEAN MODE);
I need to work with quotes because of the dash and to use the wildcard because I implement a "search as you type" functionality.
When I search for the whole term "e-magazine AG", the record is found.
Any ideas what I'm doing wrong here? I read about adding the dash to the list of word characters (config update needed) but I'm searching for a way to do this programmatically.
This clause
MATCH(name) AGAINST('+"e-magazi"*' IN BOOLEAN MODE);
Will search for a AND "e" AND NOT "magazi"; i.e. the - inside "e-magazi" will be interpreted as a not even though it is inside quotation marks.
For this reason it will not work as expected.
A solution is to apply an extra having clause with a LIKE.
I know this having is slow, but it will only be applied to the results of the match, so not too many rows should be involved.
I suggest something like:
SELECT id, name
FROM company
WHERE MATCH(name) AGAINST('magazine' IN BOOLEAN MODE)
HAVING name LIKE '%e-magazi%';
MySQL fulltext treats the word e-magazine in a text as a phrase and not as a word. Because of that it results the two words e and magazine. And while it builds the search index it does not add the e to the index because of the ft_min_word_len (default is 4 chars).
The same length limitation is used for the search query. That is the reason why a search for e-magazine returns exactly the same results as a-magazine because a and - is fully ignored.
But now you want to find the exact phrase e-magazine. By that you use the quotes and that is the complete correct way to find phrases, but MySQL does not support operators for phrases, only for words:
https://dev.mysql.com/doc/refman/5.7/en/fulltext-boolean.html
With this modifier, certain characters have special meaning at the beginning or end of words in the search string
Some people would suggest to use the following query:
SELECT id, name
FROM company
WHERE MATCH(name) AGAINST('e-magazi*' IN BOOLEAN MODE)
HAVING name LIKE 'e-magazi%';
As I said MySQL ignores the e- and searches for the wildcard word magazi*. After those results are optained it uses HAVING to aditionally filter the results for e-magazi* including the e-. By that you will find the phrase e-magazine AG. Of course HAVING is only needed if the search phrase contains the wildcard operator and you should never use quotes. This operator is used by your user and not you!
Note: As long you do not surround the search phrase with % it will find only fields that start with that word. And you do not want to surround it, because it would find bee-magazine as well. So maybe you need an additional OR HAVING name LIKE ' %e-magazi%' OR HAVING NAME LIKE '\\n%e-magazi%' to make it usable inside of texts.
Trick
But finally I prefer a trick so HAVING isn't needed at all:
If you add texts to your database table, add them additionally to a separate fulltext indexed column and replace words like up-to-date with up-to-date uptodate.
If a user searches for up-to-date replace it in the query with uptodate.
By that you can still find specific in user-specific but up-to-date as well (and not only date).
Bonus
If a user searches for -well-known huge ports MySQL treats that as not include *well*, could include *known* and *huge*. Of course you could solve that with an other extra query variant as well, but with the trick above you remove the hyphen so the search query looks simply like that:
SELECT id
FROM texts
WHERE MATCH(text) AGAINST('-wellknown huge ports' IN BOOLEAN MODE)
I am trying to follow: http://dev.mysql.com/doc/refman/4.1/en/fulltext-natural-language.html
in an attempt to improve search queries, both in speed and the ability to order by score.
However when using this SQL ("skitt" is used as a search term just so I can try match Skittles).
SELECT
id,name,description,price,image,
MATCH (name,description)
AGAINST ('skitt')
AS score
FROM
products
WHERE
MATCH (name,description)
AGAINST ('skitt')
it returns 0 results. I am trying to find out why, I think I might have set my index's up wrong I'm not sure, this is the first time I've strayed away from LIKE!
Here is my table structure and data:
Thank you!
By default certain words are excluded from the search. These are called stopwords. "a" is an example of a stopword. You could test your query by using a word that is not a stopword, or you can disable stopwords:
How can I write full search index query which will not consider any stopwords?
If you want to also match prefixes use the truncation operator in boolean mode:
*
The asterisk serves as the truncation (or wildcard) operator. Unlike the other operators, it should be appended to the word to be affected. Words match if they begin with the word preceding the * operator.
I'm trying to use wildcards to pass a stem of a word as part of a full text search in MySql. I would prefer to use match...against for the performance benefit instead of a like query.
I found this post which makes it sound as though this can be done:
MySQL fulltext with stems
...but I can't get it to work for me.
My data looks like this:
table name: "rxnorm_brands"
step_medname bn_name
Amoxicillin Wymox
Amoxicillin-Clavulanate Augmentin
This query works but uses "like":
select `step_medname`, `bn_name`
from `rxnorm_brands`
where (`bn_name` like 'Amox%' or `step_medname` like 'Amox%');
I want to use this query, but it returns nothing:
select `step_medname`, `bn_name`
from `rxnorm_brands`
where MATCH (`bn_name`, `step_medname`) AGAINST ('Amox*');
I do have a fulltext index on bn_name and step_medname. What am I doing wrong? Or can this not be done?
This can be done using IN BOOLEAN MODE, see: http://dev.mysql.com/doc/refman/5.1/en/fulltext-boolean.html.
So your query would become:
select `step_medname`, `bn_name`
from `rxnorm_brands`
where MATCH (`bn_name`, `step_medname`) AGAINST ('Amox*' IN BOOLEAN MODE);
but note that with the BOOLEAN MODE matching, rows either match or they don't - the results can no longer be ordered by relevance like they can with normal FULLTEXT searches.
The RxNorm API now has a method that will do matching of text that only approximately matches the RxNorm concept. See http://rxnav.nlm.nih.gov/RxNormAPI.html#label:23