Searching the knowledge base from 7.3.2 onwards - Lucene search operators

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    LANDESK Service Desk 7.7.x

    Below is an extract from the Lucene knowledge base which outlines the supported search operators.  I have extracted only those which I think will be used but there is more information available on their knowledge base (link below) These operators work within knowledge management search from 7.3.2 of Service Desk.

     

    NOTE: The search operators must be in upper case to be recognised as such.  For example searching on "this" and "that will not search for items with both words in but "this" AND "that" will.

     

    (extract taken from

    http://lucene.apache.org/java/2_4_0/queryparsersyntax.html)

     

    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 (see below).

    Note: The analyzer used to create the index will be used on the terms  and phrases in the query string.         So it is important to choose an analyzer that will not interfere  with the terms used in the query string.

     

    Wildcard Searches

    Lucene supports 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:

    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.

    Starting with Lucene 1.9 an additional (optional) parameter can  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

    The default that is used if the parameter is not given is 0.5.

    Boosting a Term

    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 "Apache 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

    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.         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 "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 "Apache  Lucene" use the query:

    "jakarta apache" AND "Apache 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 lucene

    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 "jakarta apache" but not "Apache  Lucene" use the query:

    "jakarta apache" NOT "Apache 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 "Apache  Lucene" use the query:

    "jakarta apache" -"Apache Lucene"

    Grouping

    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.

    Field Grouping

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

    To search for a title that contains both the word "return" and the  phrase "pink panther" use the query:

    title:(+return +"pink panther")