Version 2019-12-02
READMEdc queries can be defined according to the Apache Lucene Simple Query Parser syntax.
+ AND operation: token1+token2
| OR operation: token1|token2
- Negates a single token: -token0
" Creates a phrase: "term1 term2 ..."
* at the end of terms specifies prefix query: term*
~N at the end of terms specifies fuzzy query: term~1
~N at the end of phrases specifies near query: "term1 term2"~5
( and ) specifies precedence: token1 + (token2 | token3)
Whitespace, '\n', '\r' or '\t' may be used to delimit tokens.
The default operator is OR if no other operator is specified. For example, the following will OR token1 and token2 together: token1 token2.
Normal operator precedence will be simple order from right to left.
Escaping can be done with the escape character: \.
The following characters must be escaped: + | " ( ) ' \
Special cases:
-
Not operator: The first occurrence in a term must be escaped:
-term1-- Specifies NOT operation against term1\-term1-- Searches for the term -term1. -
Prefix query: The last character in a term must be escaped:
term1*-- Searches for the prefix term1term1\*-- Searches for the term term1*