Mysql query show no result with some bad words? - mysql

Question

I am working on an adult site, for this site I have created an internal research.
For search I use this query:
SELECT SQL_CALC_FOUND_ROWS
id_photo, title, description, model, data_ins,
MATCH(title, description, model) AGAINST('".trim(strtolower(addslashes($_GET['q'])))."') as score
FROM ".$prefix."photo
WHERE MATCH(title, description, model) AGAINST('".trim(strtolower(addslashes($_GET['q'])))."')
ORDER BY score DESC LIMIT ".$start.", ".$step."
Everything works smoothly and without php or mysql errors, but the client pointed out a strange thing to me.
eg :
searching for the word starting with "c" and ending with "ck" the
query returns no results.
searching for the word starting with "d"
and ending with "ck" the query returns the correct results.
I use something similar to this to verify if there are results:
$photo_query_id = $db->prepare("my query");
$photo_query_id->execute();
if($photo_query_id->rowCount() < 1){
//...
}
The two words are both used hundreds of times in both titles and descriptions, so why does mysql sometimes prefer not to show results?
Is there a list of bad words in some mysql config file that is blocking queries? And in case where do I find it and how do I modify it?

Answer 1

Use a BOOLEAN MODE search or use the InnoDB database engine for your table. When you do a natural language search against a MyISAM full-text index, words that appear in more than 50% of the rows are treated as stopwords.
From the documentation:
The 50% threshold can surprise you when you first try full-text searching to see how it works, and makes InnoDB tables more suited to experimentation with full-text searches. If you create a MyISAM table and insert only one or two rows of text into it, every word in the text occurs in at least 50% of the rows. As a result, no search returns any results until the table contains more rows. Users who need to bypass the 50% limitation can build search indexes on InnoDB tables, or use the boolean search mode explained in Section 12.10.2, “Boolean Full-Text Searches”]2.