Search Query Help
Contents
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.
Fields
HT Search supports fielded data. When performing a search you can either specify a field, or use the default
field. The field names and default field is implementation specific. You can search any field by typing the
field name followed by a colon ":" and then the term you are looking for. As an example, let's assume a
HT Search index contains two fields, title and text and text is the default field. If you want to find the
document entitled "The Right Way" which contains the text "don't go this way", you can enter:
title:"The Right Way" AND text:go
or
title:"Do it right" AND right
Since text is the default field, the field indicator is not required.
Note: The field is only valid for the term that it directly precedes, so the query
title:Do it right
Will only find "Do" in the title field. It will find "it" and "right" in the default field (in this case
the text field).
Term Modifiers
HT Search supports modifying query terms to provide a wide range of searching options.
Wildcard Searches
HT Search 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
HT Search 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. 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.
Proximity Searches
HT Search 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 "Indianapolis" and "sports" with
10 words of each other in a document use the search:
Indianapolis sports"~10
Range Searches
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.
Sorting is done lexicographically.
mod_date:[20020101 TO 20030101]
This will find documents whose mod_date fields have values between 20020101 and 20030101, inclusive. Note
that Range Queries are not reserved for date fields. You could also use range queries with non-date fields:
title:{Aida TO Carmen}
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
HT Search 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
Indianapolis sports
and you want the term "Indianapolis" to be more relevant boost it using the ^ symbol along with the boost
factor next to the term. You would type:
Indianapolis^4 sports
This will make documents with the term "Indianapolis" appear more relevant. You can also boost Phrase Terms as
in the example:
"Indianapolis sports"^4 "high school basketball"
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. HT Search 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. 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 "Indianapolis sports" or just "Indianapolis" use the query:
"Indianapolis sports" sports
or
"Indianapolis sports" OR sports
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 "Indianapolis sports" and "high school" use the query:
"Indianapolis sports" AND "high school"
+
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 "Indianapolis" and may contain "sports" use the query:
+Indianapolis sports
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 "Indianapolis sports" but not "high school" use the query:
"Indianapolis sports" NOT "high school"
Note: The NOT operator cannot be used with just one term. For example, the following search will return no
results:
NOT "Indianapolis sports"
-
The "-" or prohibit operator excludes documents that contain the term after the "-" symbol.
To search for documents that contain "Indianapolis sports" but not "high school" use the query:
"Indianapolis sports" -"high school"
Grouping
HT Search 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 "football" or "basketball" and "Indianapolis" use the query:
(football OR basketball) AND Indianapolis
This eliminates any confusion and makes sure you that Indianapolis must exist and either term football or
basketball may exist.
Field Grouping
HT Search 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")
Escaping Special Characters
HT Search 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