Boolean Full-Text Searches These two operators are used to change a word’s contribution to the relevance value that is assigned to a row. The  >  operator increases the contribution and the  <  operator decreases it. See the example following this list. Parentheses group words into subexpressions. Parenthesized groups can be nested. A leading tilde acts as a negation operator, causing the word’s contribution to the row’s relevance to be negative. This is useful for marking “noise”  words. A row containing such a word is rated lower than others, but is not excluded altogether, as it would be with the  -  operator. The asterisk serves as the truncation (or wildcard) operator. Unlike the other operators, it is  appended  to the word to be affected. Words match if they begin with the word preceding the  *  operator. If a word is specified with the truncation operator, it is not stripped from a boolean query, even if it is too short or a stopword. Whether a word is too short is determined from the  innodb_ft_min_token_size setting for  InnoDB  tables, or  ft_min_word_len  for  MyISAM  tables. These options are not applicable to FULLTEXT  indexes that use the ngram parser. The wildcarded word is considered as a prefix that must be present at the start of one or more words. If the minimum word length is 4, a search for  ’+ word  +the*’  could return fewer rows than a search for ’+ word  +the’ , because the second query ignores the too-short search term  the . A phrase that is enclosed within double quote ( " ) characters matches only rows that contain the phrase literally, as it was typed . The full-text engine splits the phrase into words and performs a search in the FULLTEXT  index for the words. Nonword characters need not be matched exactly: Phrase searching requires only that matches contain exactly the same words as the phrase and in the same order. For example,  "test phrase"  matches  "test, phrase" . If the phrase contains no words that are in the index, the result is empty. The words might not be in the index because of a combination of factors: if they do not exist in the text, are stopwords, or are shorter than the minimum length of indexed words. The following examples demonstrate some search strings that use boolean full-text operators: Find rows that contain at least one of the two words. Find rows that contain both words. Find rows that contain the word “apple” , but rank rows higher if they also contain “macintosh” . Find rows that contain the word “apple”  but not “macintosh” . 2209 • ’+apple -macintosh’ • ’+apple macintosh’ • ’+apple +juice’ • ’apple banana’ • " • * • ( ) • ~