Query Syntax
Using a sophisticated, yet easy-to-use query language, it is possible to construct accurate search queries on archived information. The constituents of query language are discussed further below.
Terms
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.
Fields
When performing a search, you can either specify a field, or use the default fields.
It is possible to search any field by typing the field name followed by a colon ":" and then the term sought after.
As an example, assuming one wanted to find an email with the subject "peter pan" which contains the body text "pirate ship", the following could be entered: subject:"peter pan" AND body:"pirate ship"
Please refer to Search Fields for a comprehensive list and description of all email related fields available in MailArchiva.
Boolean Operators
Boolean operators allow terms to be combined through logic operators. MailArchiva 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. The OR operator links two terms and finds a matching document if either of the terms exists 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 "apple pear" or just "apple" use the query:
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 "Apache Lucene" 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 "apple" and may contain "pear" use the query:
NOT
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 "apple pear" but not "orange grapefruit" use the query:
The "-" or prohibit operator excludes documents that contain the term after the "-" symbol. To search for documents that contain "apple pear" but not "orange grape fruit" use the query:
Grouping
MailArchiva 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 "apple" or "pear" and "grapefruit" use the query:
Field Grouping
MailArchiva supports using parentheses to group multiple clauses to a single field.
To search for a title that contains both the word "apple" and the phrase "orange grapefruit" use the query:
Wildcard Searches
MailArchiva support single and multiple character wildcard searches within single terms (not within phrase queries).
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.
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:
This search will find terms like foam and roams.
An additional (optional) parameter can be used to specify the required similarity. The value is between 0 and 1, with a value closer to 1 only terms with a higher similarity will be matched. For example:
roam~0.8
Proximity Searches
MailArchiva 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 "apple" and "pear" within 10 words of each other in a document, use the search:
Range Searches
Range Queries allow one to match documents whose field(s) values are between the lower and upper bounds specified by the Range Query. Range Queries can be inclusive or exclusive of the upper and lower bounds. Sorting is done lexicographically.
This will find documents whose sent date fields have values between 20020101 and 20030101, inclusive. Note that Range Queries are not reserved for date fields. It is possible to use range queries with non-date fields:
This will find all documents whose titles 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.
Boosting a Term
MailArchiva 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 for. The higher the boost factor, the more relevant the term will be. Boosting allows one to control the relevance of a document by boosting its term. For example, assuming one is searching for:
and one wants the term "apple" to be more relevant. Boost it using the ^ symbol along with the boost factor next to the term. Type:
This will make documents with the term apple 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).
Escaping Special Characters
MailArchiva supports escaping special characters that are part of the query syntax. The current list of special characters are:
To escape these characters use a backslash ("\") before the character. For example, to search for (1+1):2 use the query:
Regular Expression Search
A regular expression search begins and ends with /. For example, the regex search query:
all:/<6-9>{1}916?539?71?25/
will search using the regular expression "<6-9>{1}916?539?71?25".
Regular expressions are built from the following abstract syntax:
| regexp | ::= | unionexp | ||
| | | ||||
| unionexp | ::= | interexp | unionexp | (union) | |
| | | interexp | |||
| interexp | ::= | concatexp & interexp | (intersection) | [OPTIONAL] |
| | | concatexp | |||
| concatexp | ::= | repeatexp concatexp | (concatenation) | |
| | | repeatexp | |||
| repeatexp | ::= | repeatexp ? | (zero or one occurrence) | |
| | | repeatexp * | (zero or more occurrences) | ||
| | | repeatexp + | (one or more occurrences) | ||
| | | repeatexp {n} | (n occurrences) | ||
| | | repeatexp {n,} | (n or more occurrences) | ||
| | | repeatexp {n,m} | (n to m occurrences, including both) | ||
| | | complexp | |||
| complexp | ::= | ~ complexp | (complement) | [OPTIONAL] |
| | | charclassexp | |||
| charclassexp | ::= | [ charclasses ] | (character class) | |
| | | [^ charclasses ] | (negated character class) | ||
| | | simpleexp | |||
| charclasses | ::= | charclass charclasses | ||
| | | charclass | |||
| charclass | ::= | charexp - charexp | (character range, including end-points) | |
| | | charexp | |||
| simpleexp | ::= | charexp | ||
| | | . | (any single character) | ||
| | | # | (the empty language) | [OPTIONAL] | |
| | | @ | (any string) | [OPTIONAL] | |
| | | " <Unicode string without double-quotes> " | (a string) | ||
| | | ( ) | (the empty string) | ||
| | | ( unionexp ) | (precedence override) | ||
| | | < <identifier> > | (named automaton) | [OPTIONAL] | |
| | | <n-m> | (numerical interval) | [OPTIONAL] | |
| charexp | ::= | <Unicode character> | (a single non-reserved character) | |
| | | \ <Unicode character> | (a single character) |
The productions marked [OPTIONAL] are only allowed if specified by the syntax flags passed to the RegExp constructor. The reserved characters used in the (enabled) syntax must be escaped with backslash (\) or double-quotes ("..."). (In contrast to other regexp syntaxes, this is required also in character classes.) Be aware that dash (-) has a special meaning in charclass expressions. An identifier is a string not containing right angle bracket (>) or dash (-). Numerical intervals are specified by non-negative decimal integers and include both end points, and if n and m have the same number of digits, then the conforming strings must have that length (i.e. prefixed by 0's).
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