Query Syntax

Field
You can search any field by typing the field name followed by a colon ":" and then the term you are looking for. If you want to find documents which has "Fess" as the document title
title:Fess
The available fields are "url"

Sort
sort field sorts documents by a specified field name. The format is "sort:<field>.<order>"
Fess sort:content_length.desc
The available sort field are "created"

AND
AND operator is the default conjunction operator. You can omit it from a query. AND operator matches documents where both terms exist anywhere in the text of a single document.
Fess AND Solr

OR
OR operator matches documents where any terms exist anywhere in the text of a single document.
Fess OR Solr

Wildcard
single and multiple character wildcard searches within single terms are supported. "?" symbol is a single character wildcard search
Fess*
or
Fe?s

Range
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.
If you want to find documents whose content_length fields have values between 1000 and 10000
content_length:[1000 TO 10000]
If you want to exclude the upper and lower bounds

Boost
To boost a term use the "^" symbol with a boost factor (a number) at the end of the term you are searching.
Fess^100

Fuzzy
To do a fuzzy search use the "~" symbol at the end of a single word term. For example to search for a term similar in spelling to "Fess" use the fuzzy search:
Fess~0.5