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

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.

Related

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.

mysql boolean mode fulltext search with wildcards and literals

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)

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

using LIKE operator in mysql

I want search companies from my company table when i give company name...here am using like operator
eg: saravana stores
it gives the result saravana stores texttiles,saravana stores thanga maligai,etc(which is contained with saravana stroes...coz of using LIKE operator)
Now my problem is when i give lcd projectors in the companyname, also want to fetch the records which are contained with the only projector word...but like operator gave the results with the 'lcd projector'
am making clear?
Try:
WHERE (name LIKE '%saravana%' OR name LIKE '%stores%')
This has two disadvantages:
It can't use an index so it will be slow.
It can give you matches you don't want like 'bestorest' matches '%stores%'.
You might want to use a full text search instead. You could also consider an external engine such as Lucene.
If you want proper fultext search, I highly recommend trying Lucene or Sphinx.
I know it would get a little complicated, but it's worth it for the end result.
Mark Byers is right.
To get more efficiency
After query dividing to words you can modify search input to get word base and unify searching to get smth lika:
WHERE (name LIKE '%sarava%' OR name LIKE '%stor%')

Search prob in mysql query

Is there any way to search like below criteria in mysql?
If any the pl reply.
if i search with "murray's" then it then it will return fine data for "murray's" but it should also return data for "murrays" means same word without apostrophy(').
same way if i search without apostrophy('), the it will search also with apostrophy(').
at last
if search query is "murray's", the it will return "murray's" and "murrays" also.
and
if search query is "murrays", the it will return "murrays" and "murray's" also.
Thanks in advance
Your best bet is to create a Full Text Index on your table.
You can then query it as:
select *
from restaurants
where match(name) against ('murrays')
Barring that, you can use SOUNDEX or SOUNDS LIKE in your query. The following two queries are exactly identical:
select *
from restaurants
where soundex(name) = soundex('murrays')
select *
from restaurants
where name sounds like 'murrays'
Also note that MySQL uses the original SOUNDEX algorithm, not the more recent one. Therefore, it will return arbitrary length strings. If you've used SOUNDEX before, just make sure you take that into account.