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 conservation.
A Phrase is a group of words surrounded by double quotes such as "water conservation".
All terms are case insensitive.
Multiple terms can be combined together with Boolean operators to form a more complex query (see below).
Term modifiers provide a wider range of searching options:
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:
Multiple character wildcard searches looks for 0 or more characters. For example, to search for test, tests or tester, you can use the search:
You can also use the wildcard searches in the middle of a term.
Note: You cannot use a * or ? symbol as the first character of a search.
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:
This search will find terms like foam and roams.
To do a proximity search use the tilde, "~", symbol at the end of a Phrase. For example to search for "water" and "conservation" within 5 words of each other in a page use the search:
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
and you want the term "water" to be more relevant boost it using the ^ symbol along with the boost factor next to the term. You would type:
This will make documents with the term "water" appear more relevant. You can also boost Phrase Terms as in the example:
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. 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. The OR operator links two terms and finds a matching document if either of the terms exist in a document. This is equivalent to a union using sets. The symbol || can be used in place of the word OR.
To search for documents that contain either "water conservation" or just "ecosystem" use the query:
or
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 "water conservation" and "aquatic ecosystem" use the query:
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 "conservation" and may contain "ecosystem" use the query:
The NOT operator excludes documents that contain the term after NOT. 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 "water conservation" but not "aquatic ecosystem" use the query:
Note: The NOT operator cannot be used with just one term. For example, the following search will return no results:
The "-" or prohibit operator excludes documents that contain the term after the "-" symbol.
To search for documents that contain "water conservation" but not "aquatic ecosystem" use the query:
Parentheses can be used 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 "conservation" or "preservation" and "ecosystem" use the query:
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:
The Apache Lucene framework v4.7.2 is utilised to implement the search facility.