MySQL match against sub select - mysql

I have a query on a full text column 'abstract':
SELECT title
FROM citation
WHERE MATCH(abstract)
AGAINST ('+orange' IN BOOLEAN MODE)
My question: I want to generate the AGAINST clause using results from a sub select, eg (pseudocode):
SELECT title
FROM citation
WHERE MATCH(abstract)
AGAINST (
CONCAT("'","+",
SELECT names
FROM fruits
WHERE type = "citrus"),"' "
), "IN BOOLEAN MODE"
)
Is this possible?

The arguument in against needs to be a constant.
Take a look at this document here. click to see
Your query is much likely to work with LIKE however using this makes your query a lot slower.
Or you could do something like
SET #finding_element=(SELECT c1.full_name FROM customer c1 WHERE c1.id=2); SELECT c.full_name FROM customer c WHERE MATCH(c.full_name) AGAINST((#finding_element));
(query I have is used is just for reference)
Happy Learning

Related

SQL show results for A column first then show results for B column

I want SQL to show / order the results for the column name first then show results for the description column last.
Current SQL query:
SELECT * FROM products WHERE (name LIKE '%$search_query%' OR description LIKE '%$search_query%')
I tried adding order by name, description [ASC|DESC] on the end but that didn't work.
It's for optimizing the search results. If a certain word is found in description it should go last if a certain word is also found in the name column.
You can use a CASE statement in an ORDER BY to prioritize name. In the example below all results where name is matched will come first because the CASE statement will evaluate to 1 whereas all other results will evaluate to 2.
I'm not sure by your problem description what exactly you want the behavior to be, but you can certainly use this technique to create more refined cases to prioritize your results.
SELECT *
FROM products
WHERE (name LIKE '%$search_query%' OR description LIKE '%$search_query%')
ORDER BY CASE WHEN name LIKE '%$search_query%' THEN 1 ELSE 2 END
If you want the names first, the simplest order by is:
order by (name like '%$search_query%') desc
MySQL treats booleans as numbers in a numeric context, with "1" for true and "0" for false.
While this is undocumented, when results sets combined by a UNION ALL and not sorted afterwards, they stay in the order returned, as UNION ALL just adds new results to the bottom of the result set. This should work for you:
SELECT * FROM products
WHERE name LIKE '%$search_query%'
UNION ALL
SELECT * FROM products
WHERE (description LIKE '%$search_query%' AND name NOT LIKE '%$search_query%')

having with match and group_concat in mysql

I' trying to write a MYSQL query which looks for a string in an aggregation of fields.
The following query finds all the concatenations where "io sono" is present:
SELECT chapter, GROUP_CONCAT(text_search) AS aggregated_chapters
FROM bible_it_cei_2008
GROUP BY chapter
HAVING aggregated_chapters LIKE '%io sono%';
However, trying to use MATCH... AGAINST instead of LIKE:
SELECT chapter, GROUP_CONCAT(text_search) AS aggregated_chapters
FROM bible_it_cei_2008
GROUP BY chapter
HAVING MATCH ( aggregated_chapters ) AGAINST ( '+"io sono"' IN BOOLEAN MODE);
returns the error:
#1210 - Incorrect arguments to MATCH
Isn't there any way to use MATCH AGAINST with GROUP_CONCAT?
Isn't there any way to use MATCH AGAINST with GROUP_CONCAT?
No. That's not the way FULLTEXT search works in MySQL.
If your table contains the columns chapter and text_search, and you hope to find the values of chapter matching text search, you want something like this.
SELECT chapter,
MATCH(text_search) AGAINST ('+"io sono"' IN NATURAL LANGUAGE MODE) AS score
FROM bible_it_cei_2008
To get this to work you'll need to create an appropriate FULLTEXT index.

MySQL wildcard Like query with multiple words

I have a mysql query as follows.
$query="SELECT name,activity FROM appid
where result > 5 AND name LIKE :term ORDER BY name ASC LIMIT 0,40";
$result = $pdo->prepare($query);
$result->bindvalue(':term','%'.$_GET["q"].'%',PDO::PARAM_STR);
$result->execute();
What i want to do is this.
I have and entry like this that i want to find
'News & Weather'
However when i type
'news weather'
it of course will not find it. How can i be able to type that and retrieve that entry?
Regular expressions can do the trick:
select *
from appid
where name rlike 'news|weather' -- Matches 'news' or 'weather'
Another example:
select *
from appid
where name rlike 'news.*weather' -- Matches 'news' and 'wether'
-- with any characters in-between or none at all
-- (ordered)
Just one more:
select *
from appid
where name rlike '^news.{1,}weather$' -- Matches any text that starts with 'news'
-- and has at least one character before
-- ending with 'weather'
Regular espressions can be used to create very complicated filters on text fields. Read the link above for more information.
If you can add a full-text index to your table, Full-text search might be the better way to go with this. Specifically, a boolean Full-Text search:
select *
from appid
where match(name) against (+news +weather)
I believe the only way possible are through code:
Option A: Replace the spaces in your query parameter with '%' in code, but that of course will make the multiple words ordered
Option B: Split your parameter on spaces and dynamically construct your query with as many LIKEs as needed, adding additional ":termN" parameters for each one.

SQL Server Full-Text Search for exact match with fallback

First off there seems to be no way to get an exact match using a full-text search. This seems to be a highly discussed issue when using the full-text search method and there are lots of different solutions to achieve the desired result, however most seem very inefficient. Being I'm forced to use full-text search due to the volume of my database I recently had to implement one of these solutions to get more accurate results.
I could not use the ranking results from the full-text search because of how it works. For instance if you searched for a movie called Toy Story and there was also a movie called The Story Behind Toy Story that would come up instead of the exact match because it found the word Story twice and Toy.
I do track my own rankings which I call "Popularity" each time a user access a record the number goes up. I use this datapoint to weight my results to help determine what the user might be looking for.
I also have the issue where sometimes need to fall back to a LIKE search and not return an exact match. I.e. searching Goonies should return The Goonies (most popular result)
So here is an example of my current stored procedure for achieving this:
DECLARE #Title varchar(255)
SET #Title = '"Toy Story"'
--need to remove quotes from parameter for LIKE search
DECLARE #Title2 varchar(255)
SET #Title2 = REPLACE(#title, '"', '')
--get top 100 results using full-text search and sort them by popularity
SELECT TOP(100) id, title, popularity As Weight into #TempTable FROM movies WHERE CONTAINS(title, #Title) ORDER BY [Weight] DESC
--check if exact match can be found
IF EXISTS(select * from #TempTable where Title = #title2)
--return exact match
SELECT TOP(1) * from #TempTable where Title = #title2
ELSE
--no exact match found, try using like with wildcards
SELECT TOP(1) * from #TempTable where Title like '%' + #title2 + '%'
DROP TABLE #TEMPTABLE
This stored procedure is executed about 5,000 times a minute, and crazy enough it's not bringing my server to it's knees. But I really want to know if there was a more efficient approach to this? Thanks.
You should use full text search CONTAINSTABLE to find the top 100 (possibly 200) candidate results and then order the results you found using your own criteria.
It sounds like you'd like to ORDER BY
exact match of the phrase (=)
the fully matched phrase (LIKE)
higher value for the Popularity column
the Rank from the CONTAINSTABLE
But you can toy around with the exact order you prefer.
In SQL that looks something like:
DECLARE #title varchar(255)
SET #title = '"Toy Story"'
--need to remove quotes from parameter for LIKE search
DECLARE #title2 varchar(255)
SET #title2 = REPLACE(#title, '"', '')
SELECT
m.ID,
m.title,
m.Popularity,
k.Rank
FROM Movies m
INNER JOIN CONTAINSTABLE(Movies, title, #title, 100) as [k]
ON m.ID = k.[Key]
ORDER BY
CASE WHEN m.title = #title2 THEN 0 ELSE 1 END,
CASE WHEN m.title LIKE #title2 THEN 0 ELSE 1 END,
m.popularity desc,
k.rank
See SQLFiddle
This will give you the movies that contain the exact phrase "Toy Story", ordered by their popularity.
SELECT
m.[ID],
m.[Popularity],
k.[Rank]
FROM [dbo].[Movies] m
INNER JOIN CONTAINSTABLE([dbo].[Movies], [Title], N'"Toy Story"') as [k]
ON m.[ID] = k.[Key]
ORDER BY m.[Popularity]
Note the above would also give you "The Goonies Return" if you searched "The Goonies".
If got the feeling you don't really like the fuzzy part of the full text search but you do like the performance part.
Maybe is this a path: if you insist on getting the EXACT match before a weighted match you could try to hash the value. For example 'Toy Story' -> bring to lowercase -> toy story -> Hash into 4de2gs5sa (with whatever hash you like) and perform a search on the hash.
In Oracle I've used UTL_MATCH for similar purposes. (http://docs.oracle.com/cd/E11882_01/appdev.112/e25788/u_match.htm)
Even though using the Jaro Winkler algorithm, for instance, might take awhile if you compare the title column from table 1 and table 2, you can improve performance if you partially join the 2 tables. I have in some cases compared person names on table 1 with table 2 using Jaro Winkler, but limited results not just above a certain Jaro Winkler threshold, but also to names between the 2 tables where the first letter is the same. For instance I would compare Albert with Aden, Alfonzo, and Alberto, using Jaro Winkler, but not Albert and Frank (limiting the number of situations where the algorithm needs to be used).
Jaro Winkler may actually be suitable for movie titles as well. Although you are using SQL server (can't use the utl_match package) it looks like there is a free library called "SimMetrics" which has the Jaro Winkler algorithm among other string comparison metrics. You can find detail on that and instructions here: http://anastasiosyal.com/POST/2009/01/11/18.ASPX?#simmetrics

SQL search result ranking

I have a table call objects which there are the columns:
object_id,
name_english(vchar),
name_japanese(vchar),
name_french(vchar),
object_description
for each object.
When a user perform a search, they may enter either english, japanese or french... and my sql statement is:
SELECT
o.object_id,
o.name_english,
o.name_japanese,
o.name_french,
o.object_description
FROM
objects AS o
WHERE
o.name_english LIKE CONCAT('%',:search,'%') OR
o.name_japanese LIKE CONCAT('%',:search,'%') OR
o.name_french LIKE CONCAT('%',:search,'%')
ORDER BY
o.name_english, o.name_japanese, o.name_french ASC
And some of the entries are like:
Tin spoon,
Tin Foil,
Doctor Martin Shoes,
Martini glass,
Cutting board,
Ting Soda.
So, when the user search the word "Tin" it will return all results of these, but instead I just want to return the results which specific include the term "Tin" or displaying the result and rank them by relevance order. How can I achieve that?
Thanks.
You can use MySQL FULLTEXT indices to do that. This requires the MyISAM table type, an index on (name_english, name_japanese, name_french, object_description) or whatever fields you want to search on, and the appropriate use of the MATCH ... AGAINST operator on exactly that set of columns.
See the manual at http://dev.mysql.com/doc/refman/5.5/en/fulltext-search.html, and the examples on the following page http://dev.mysql.com/doc/refman/5.5/en/fulltext-natural-language.html
After running the query above , you will get all sort of results including ones that you are not interested, but you can then use regular expressions on the above results(returned by mysql server) set to filter out what u need.
This should do the trick - you may have to filter out duplicates, but the basic idea is obvious.
SELECT
`object`.`object_id`,
`object`.`name_english`,
`object`.`name_japanese`,
`object`.`name_french`,
`object`.`object_info`, 1 as ranking
FROM `objects` AS `object`
WHERE `object`.`name_english` LIKE CONCAT(:search,'%') OR `object`.`name_japanese` LIKE CONCAT(:search,'%') OR `object`.`name_french` LIKE CONCAT(:search,'%')
union
SELECT
`object`.`object_id`,
`object`.`name_english`,
`object`.`name_japanese`,
`object`.`name_french`,
`object`.`object_info`, 10 as ranking
FROM `objects` AS `object`
WHERE `object`.`name_english` LIKE CONCAT('%',:search,'%') OR `object`.`name_japanese` LIKE CONCAT('%',:search,'%') OR `object`.`name_french` LIKE CONCAT('%',:search,'%')
ORDER BY ranking, `object`.`name_english`, `object`.`name_japanese`, `object`.`name_french` ASC