Terms and Phrases

A query is broken up into terms and operators. There are two types of terms: Single Terms and Phrases. A Single Term is a single word such as:

test OR hello

A Phrase is a group of words surrounded by double quotes such as:

"hello dolly"

Multiple terms can be combined together with Boolean operators to form a more complex query.

Lucene supports fielded data. When performing a search you can either specify a single target field, or multiple target fields, or leave as default in order to perform a search across all fields. You can search any field by typing the field name followed by a colon ":" and then the single term or phrase you are looking for:

Headline:"The Right Way"

or:

Headline,Caption:"The Right Way"

or:

Headline:"Do it right" AND right

In the latter case the phrase 'Do it right' targets the Headline field and the term 'right'; targets all fields. Note: The field is only valid for the term that it directly precedes, so the query:

Headline:Do it right

Will only search for "Do" in the Headline field. It will search for "it" and "right" in all fields.

NOTE: Where field names contain multiple words separated by a space, as in 'Body Text', replace the space with a dash, as in:

Body-Text:"Do it right"

Lucene supports modifying query terms to provide a wide range of searching options.

Lucene supports single and multiple character wildcard searches. To perform a single character wildcard search use the '?' symbol. To perform a multiple character wildcard search use the '*' symbol.

The single character wildcard search looks for terms that match that with the single character replaced. For example, to search for 'text' or 'test' you can use the search:

te?t

Multiple character wildcard searches looks for 0 or more characters. For example, to search for test, tests or tester, you can use the search:

test*

You can also use the wildcard searches in the middle of a term.

te*t

Note: You cannot use a * or ? symbol as the first character of a search.

Lucene supports fuzzy searches based on the Levenshtein Distance, or Edit Distance algorithm. To do a fuzzy search use the tilde, '~', symbol at the end of a Single word Term. For example to search for a term similar in spelling to 'roam' use the fuzzy search:

roam~

This search will find terms like foam and roams.

SCC provides a Lucene search term expansion feature using an editable synonyms list. To perform a synonym search add the dollar, '$', symbol immediately prior to the target field or fields, or if no target field is specified, immediately prior to the colon, ':', symbol which usually separates the target field name from the search term. For example, to perform a synonym expansion query for 'photo' you can use the search:

$Headline:photo

or:

$Headline,Caption:photo

or:

$:photo

This search will find terms like photo, glossy, image, likeness, photograph, picture, print, shot, snapshot within the specified target fields.

Lucene supports finding words are a within a specific distance away. To do a proximity search use the tilde, '~', symbol at the end of a Phrase. For example to search for 'apache' and 'jakarta' within 10 words of each other in a document use the search:

"jakarta apache"~10

Range Queries allow one to match documents whose field(s) values are between the lower and upper bound specified by the Range Query. Range Queries can be inclusive or exclusive of the upper and lower bounds.

Content-Date: [20010101 TO 20011231]

This will find documents whose Content-Date fields have values between 20010101 and 20011231, inclusive. Note that Range Queries are not reservedfor date fields. You could also use range queries with non-date fields:

Headline:{Aida TO Carmen}

This will find all documents whose Headlines are between Aida and Carmen, but not including Aida and Carmen. Inclusive range queries are denoted by square brackets. Exclusive range queries are denoted by curly brackets.

Lucene provides the relevance level of matching documents based on the terms found. To boost a term use the caret, '^', symbol with a boost factor (a number) at the end of the term you are searching. The higher the boost factor, the more relevant the term will be.

Boosting allows you to control the relevance of a document by boosting its term. For example, if you are searching for:

jakarta apache

and you want the term 'jakarta' to be more relevant boost it using the '^' symbol along with the boost factor next to the term. You would type:

jakarta^4 apache

This will make documents with the term jakarta appear more relevant. You can also boost Phrase Terms as in the example:

"jakarta apache"^4 "jakarta lucene"

By default, the boost factor is 1. Although the boost factor must be positive, it can be less than 1 (e.g. 0.2)

Boolean operators allow terms to be combined through logic operators. Lucene supports AND, '+', OR, NOT and '-' as Boolean operators(Note: Boolean operators must be ALL CAPS).

OR

The OR operator is the default conjunction operator. This means that if there is no Boolean operator between two terms, the OR operator is used. The OR operator links two terms and finds a matching document if either of the terms exist in a document.

To search for documents that contain either 'jakarta apache' or just 'jakarta' use the query:

"jakarta apache" jakarta

or

"jakarta apache" OR jakarta

AND

The AND operator matches documents where both terms exist anywhere in the text of a single document. This is equivalent to an intersection using sets. The symbol '&' can be used in place of the word 'AND'.

To search for documents that contain 'jakarta apache' and 'jakarta lucene' use the query:

"jakarta apache" AND "jakarta lucene"

+

The '+' or required operator requires that the term after the '+' symbol exist somewhere in a the field of a single document.

To search for documents that must contain 'jakarta' and may contain 'lucene' use the query:

+jakarta apache

NOT

The NOT operator excludes documents that contain a term. This is equivalent to a difference using sets. The symbol '!' can be used in place of the word 'NOT'.

To search for documents that contain 'jakarta apache' but not 'jakarta lucene' use the query:

"jakarta apache" NOT "jakarta lucene"

Note: The NOT operator cannot be used with just one term. For example, the following search will return no results:

NOT "jakarta apache"

-

The '-' or prohibit operator excludes documents that contain the term after the '-' symbol. To search for documents that contain 'jakarta apache' but not 'jakarta lucene' use the query:

"jakarta apache" -"jakarta lucene"

Lucene supports using parentheses to group clauses to form sub queries. This can be very useful if you want to control the boolean logic for a query.

To search for either "jakarta" or "apache" and "website" use the query:

(jakarta OR apache) AND website

This eliminates any confusion and makes sure you that website must exist and either term jakarta or apache may exist.

Lucene supports using parentheses to group multiple clauses to a single field.

To search for a record that contains both the word 'return' and the phrase 'pink panther' in the Headline field use the query:

Headline:(+return +"pink panther")

Lucene supports escaping special characters that are part of the query syntax. The current list special characters are:

+ - && || ! ( ) { } [ ] ^ " ~ * ? : \

To escape these character use the \ before the character. For example to search for (1+1):2 use the query:

\(1\+1\)\:2