Fulltext Search HOWTO

Search 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.

*
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.

> <
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 subexpressions. 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.

The following examples demonstrate some search strings that use boolean full-text operators:

Bundeskanzler Fischer
Find rows that contain at least one of the two words.

+Bundeskanzler +Schröder
Find rows that contain both words.

+Bundeskanzler Iraq
Find rows that contain the word ``Bundeskanzler'', but rank rows higher if they also contain ``Iraq''.

+Bundeskanzler -Iraq
Find rows that contain the word ``Bundeskanzler'' but not ``Iraq''.

Bundeskanzler*
Find rows that contain words such as ``Bundeskanzler'', ``Bundeskanzlamt'', ``Bundeskanzlerin''.

"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.

+Bundeskanzler +(>turnover <power)
Find rows that contain the words ``Bundeskanzler'' and ``turnover'', or ``Bundeskanzler'' and ``Merkel'' (in any order), but rank ``Bundeskanzler turnover'' higher than ``Bundeskanzler Merkel''.