The search supports the following operators:
'+' - A leading plus sign indicates that this word must be present in every row returned.
'-' - A leading minus sign indicates that this word must not be present in any row returned.
'(no operator)' - By default (when neither + nor - is specified) the word is optional, but the rows that contain it will be rated higher.
'>' '<' - 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 below.
'( )' - Parentheses are used to group words into sub-expressions. Parenthesized groups can be nested.
'~' - A leading tilde acts as a negation operator, causing the word's contribution to the row relevance to be negative. It's useful for marking noise words. A row that contains such a word will be rated lower than others, but will not be excluded altogether, as it would be with the - operator.
'*' - An asterisk is the truncation operator. Unlike the other operators, it should be appended to the word.
'"' - A phrase that is enclosed within double quote (`"') characters matches only rows that contain the phrase literally, as it was typed.
The following examples demonstrate some search strings that use boolean full-text operators:
'apple banana' - Find rows that contain at least one of the two words.
'+apple +juice' - Find rows that contain both words.
'+apple macintosh' - Find rows that contain the word ``apple'', but rank rows higher if they also contain ``macintosh''.
'+apple -macintosh' - Find rows that contain the word ``apple'' but not ``macintosh''.
'+apple +(turnover strudel)' - Find rows that contain the words ``apple'' and ``turnover'', or ``apple'' and ``strudel'' (in any order), but rank ``apple turnover'' higher than ``apple strudel''.
'apple*' - Find rows that contain words such as ``apple'', ``apples'', ``applesauce'', or ``applet''.
'"some words"' - Find rows that contain the exact phrase ``some words'' (for example, rows that contain ``some words of wisdom'' but not ``some noise words''). Note that the `"' characters that surround the phrase are operator characters that delimit the phrase. They are not the quotes that surround the search string itself.