The way to conduct a search for specific data is by accessing the database and filling in one or more of the boxes as appropriate. You can do this by simply inserting a word or words. But more flexibility can be obtained by incorporating the symbols listed below. In each case an example is provided:
If words are enclosed within double quotes (“"”) the search will result only in rows that contain the words literally, as they were typed. The full-text engine splits the phrase into words, performs a search in the FULLTEXT index for the words. Note that the “"” characters that enclose the phrase are characters that delimit the phrase. They are not the quotes that enclose the search string itself.
Example: "Amanita muscaria" will search out all rows that contain exactly that combination and spacing
Entering a plus sign before a word indicates that this word must be present in each row that is returned for your search.
Example1: '+Amanita +muscaria' will find the rows that contain both words.
Example2: '+Amanita muscaria' will find rows that contain the word Amanita, but rank rows higher if they also contain muscaria.
Example: '+Amanita -muscaria' will find rows that contain the word Amanita but will exclude those identified as muscaria.
Note: The use of the minus sign acts only to exclude rows that are otherwise matched by other search terms. Thus, a search that contains only terms preceded by a minus sign returns an empty result. It does not return “all rows except those containing any of the excluded terms.”
-
> <
These two signs are used to change a word's contribution to the relevance value that is assigned to a row. When placed before a word the > sign increases the contribution and the < sign decreases it.
-
( )
Parentheses group words into subexpressions. Parenthesized groups can be nested.
Example: '+Amanita +(>muscaria<var muscaria var aureola )'
Find rows that contain the words Amanita and muscaria, or Amanita and muscaria var aureola (in any order), but rank Amanita muscaria higher than Amanita muscaria var aureola.
-
~
A tilde sign before a word causes that 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 when using a minus sign.
Example: '+Amanita ~muscaria' will find rows that contain the word Amanita, but if the row also contains the word muscaria, rate it lower than if row does not. This is softer than a search for '+Amanita -muscaria', for which the presence of muscaria causes the row not to be returned at all.
The asterisk serves as the truncation (or wildcard) sign. Unlike the other operators, it should be appended to the word to be affected. Words match if they begin with the word preceding the * sign.
Example: 'aerug*' will find rows that contain words such as aeruginea, or aeruginosa.
