Query Syntax

To search Senna indexes, query syntax like BOOLEAN MODE of MySQL is provisioned. You can use them not only for Senna + MySQL binding and other bindings.

Pragma for setting query handling can be added on top of query string:

• Pragma have to be located on top of query string.
• To use multiple pragma, don't put blank space between each of them (don't put blank space on top of the query either).

*EN1[,N2] (N1 and N2 are numeric number)

When the search result is lesser then N1, Senna automatically change handling way as ordering by perfect matching -> unsplit word matching -> partial matching. In that case, scores for items that isn't perfect matching decrease N2 point. If N2 is omitted, N2 is set default value (=2). In case negative number set on N1, Senna handles as below.

-1: only search by perfect matching.
-2: only search by unsplit word matching.
-3: only search by perfect matching and unsplit word matching.
-4: only search by pertial matcing.
-5: only search by perfect matching and pertial matching.
-6: only search by unsplit matching and pertial matching.
-7: search by perfect matcing, unsplit word matching, and pertial matching.

example:

*E10,3

Search results are less than 10, Senna changes search way and decrements scores 3 points sequencially.

*DOperator

Specify which operator uses when operator is omitted.

Specifyable operators are OR, +, and -. OR works as BOOLEAN MODE of MySQL. + works as most web search engine.

example 1:

*D+ abc def

Search documents that have both "abc" and "def".

example 2:

*DOR abc def

Search documents that have whether "abc" or "def".

*W[N[:W]][,N[:W]]...

Search documents that has word in the section specified by N. Score are multiplied by W per a section.If W is not specified, W is 1.W is able to be specified to negative value.

+word

A plus operator indicates that this word must be present in matching document. (What is called AND)

-word

A minus operator indicates that this word must not be present in any matching document. (What is called NOT)

ORword

A OR operator indicates the word is optional, but the document that contains the specified word is rated higher.

(What is called OR) note: OR have to be written by capital.

~word

A ~ operator indicates that this word can be presented, but the document that contains the specified word is rated lower.

<word or >word

Decrease the word's contribution (<). Increase the word's contribution (>).

(word operators)

This operator grouplize the word and operators.

For example: -(+Foo +Bar)

word*

This operator indicates that a word which beginning with the specified word in matching document.

"word"

If the operator is used, only matches documents contains the specified phrase.

*S[N]"String"

Search documents that is related to the specfied string. [Number] sets the number of selected characters.

*N[N]"String"

Search documents that has words in "Search" with located adjacent each other. The [N] sets the maximum number of neighborhood words. For N-gram, it sets the number of characters.