MySql full text search to consider extra s es - mysql

I need a full text search query to search a word, also it should consider extra s and es at the end. If I put * at the end it matches with lot of extra characters as well which are not needed.
eg;
select item_description from item_description_mapping where match(item_description)
against('+maintain*' in boolean mode) ;
This query gives results
Maintain
maintainance
Maintains
Here we require only maintain, maintains like that not maintainance.
Is there something like regex combination with boolean mode in full text search or we can use length function with exact match??
Thanks,
Ashish

I got answer for this,
select * from index_table where item_name rlike '[[:<:]]preform[s]*[es]*[ies]*[[:>:]]';
I am posting this here coz it might be helpful for others in need.
Thanks,
Ashish

Related

MySQL String Comparison with Wildcards

I wrote a query where a user can input a string and get the data related to that string back from the database.
For example, a user will input Apple even though the full name is Apple Inc.
The code would be laid out as so...
and Description like '%Apple%'
The problem with this is, it will return Snapple along with Apple.
Aside from removing the first "%" wildcard and making the user type more, how can I limit the results to just Apple?
Use a regular expression:
WHERE Description RLIKE '[[:<:]]apple[[:>:]]'
[[:<:]] matches the beginning of a word, [[:>:]] matches the end of a word.
See the documentation for all the regexp operators supported by MySQL
Firstly - string comparison with wild cards (especially leading wild cards) doesn't really scale using "like". You might want to look at full-text searching instead. This basically gives you "google-like" text searching capabilities.
To answer your question, in most cases, "Apple" is a better match than "Snapple" for the term "apple". So, you could include the concept of "match quality" in the search - something like:
select *, 10 as MatchQuality
from table
where description like 'Apple'
union
select *, 5 as MatchQuality
from table
where description like 'Apple%'
union
select *, 1 as MatchQuality
from table
where description like '%Apple%'

mysql fulltext boolean search with asterix

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.

How to use prefix wildcards like '*abc' with match-against

I have the following query :
SELECT * FROM `user`
WHERE MATCH (user_login) AGAINST ('supriya*' IN BOOLEAN MODE)
Which outputs all the records starting with 'supriya'.
Now I want something that will find all the records ending with e.g. 'abc'.
I know that * cannot be preappended and it doesn't work either and I have searched a lot but couldn't find anything regarding this.
If I give query the string priya ..it should return all records ending with priya.
How do I do this?
Match doesn't work with starting wildcards, so matching with *abc* won't work. You will have to use LIKE to achieve this:
SELECT * FROM user WHERE user_login LIKE '%abc';
This will be very slow however.
If you really need to match for the ending of the string, and you have to do this often while the performance is killing you, a solution would be to create a separate column in which you reverse the strings, so you got:
user_login user_login_rev
xyzabc cbazyx
Then, instead of looking for '%abc', you can look for 'cba%' which is much faster if the column is indexed. And you can again use MATCH if you like to search for 'cba*'. You will just have to reverse the search string as well.
I believe the selection of FULL-TEXT Searching isn't relevant here. If you are interested in searching some fields based on wildcards like:
%word% ( word anywhere in the string)
word% ( starting with word)
%word ( ending with word)
best option is to use LIKE clause as GolezTrol has mentioned.
However, if you are interested in advanced/text based searching, FULL-TEXT search is the option.
Limitations with LIKE:
There are some limitations with this clause. Let suppose you use something like '%good' (anything ending with good). It may return irrelevant results like goods, goody.
So make sure you understand what you are doing and what is required.

Mysql full text search exact phrase problem

Using full text search in mysql I'd like to have exact phrase:
"romantic dinner" to be found.
But I also would like each of the words could have synonyms like:
"romantic dinners" to be found for example (our language has great problem where every word has 8 endings like)...
I tried:
+"romantic (dinner dinners)" and
"romantic +(dinner dinners)"
but nothing seems to get results... Is it possible to make some logical OR inside exact search?
UPDATE: TO make it one sentance question: Is there a way to put some logical operators in exact match ("") in full text search?
It will only partially your problem, but there is a soundex() function in mysql which transform the given string to a soundex representation. Similars string should have the same soundex representation so it's maybe a start.
Hope this helps.
If '"roman* dinn*" doesn't work for you, it might be time to look into something like Solr: http://lucene.apache.org/solr/ which will allow for more sophisticated searches, and might already have a stemmer for your language.
SELECT field_name FROM table_name WHERE MATCH(field_name) AGAINST('romantic* dinner*' IN BOOLEAN MODE)...
definitely you can use + and - to further refining your results
reference: http://dev.mysql.com/doc/refman/5.0/en/fulltext-boolean.html

Is it possible to stem full text match queries in MySql

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