Overview

NeoRef Metadata Search applies Apache Lucene as the search middleware, which provides a rich query language.

Simple Search

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.

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).

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.

Examples:

1. information AND retrieval

2. +“digital library” -profit

Term Modifiers

NeoRef Metadata Search supports modifying query terms to provide a wide range of searching options.

Wildcard Searches

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.

Fuzzy Searches

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

Proximity Searches

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 a "apache" and "jakarta" within 10 words of each other in a document use the search:

	"jakarta apache"~10

Advanced Search

Type any term or phrases into the appropriate fields you want, and if there are two or more fields for the query, they will be applied as AND Boolean operator.