C# (CSharp) Lucene.Net.QueryParsers Namespace

• a plus (+) or a minus (-) sign, indicating that the clause is required or prohibited respectively; or
• a term followed by a colon, indicating the field to be searched. This enables one to construct queries which search multiple fields.

• a term, indicating all the documents that contain this term; or
• a nested query, enclosed in parentheses. Note that this may be used with a +/- prefix to require any of a set of terms.

 Query  ::= ( Clause )* Clause ::= ["+", "-"] [<TERM> ":"] ( <TERM> | "(" Query ")" ) 

Examples of appropriately formatted queries can be found in the query syntax documentation.

In {@link RangeQuery}s, QueryParser tries to detect date values, e.g. date:[6/1/2005 TO 6/4/2005] produces a range query that searches for "date" fields between 2005-06-01 and 2005-06-04. Note that the format of the accepted input depends on {@link #SetLocale(Locale) the locale}. By default a date is converted into a search term using the deprecated {@link DateField} for compatibility reasons. To use the new {@link DateTools} to convert dates, a {@link Lucene.Net.Documents.DateTools.Resolution} has to be set.

The date resolution that shall be used for RangeQueries can be set using {@link #SetDateResolution(DateTools.Resolution)} or {@link #SetDateResolution(String, DateTools.Resolution)}. The former sets the default date resolution for all fields, whereas the latter can be used to set field specific date resolutions. Field specific date resolutions take, if set, precedence over the default date resolution.

If you use neither {@link DateField} nor {@link DateTools} in your index, you can create your own query parser that inherits QueryParser and overwrites {@link #GetRangeQuery(String, String, String, boolean)} to use a different method for date conversion.

Note that QueryParser is not thread-safe.