lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Matthew Hall <mh...@informatics.jax.org>
Subject Re: Query any data
Date Fri, 10 Apr 2009 13:25:20 GMT
I think I would tackle this in a slightly different manner.

When you are creating this index, make sure that that field has a
default value. Make sure this value is something that could never appear
in the index otherwise. Then, when you goto place this field into the
index, either write out your actual value, or the default one.

Then when you get the document back, you can look at that field, and
solve your question. You can also craft queries that specifically avoid
entries that don't have a value in this field with a not clause.

Hope this helps,

Matt

Erick Erickson wrote:
> searching for fieldname:* will be *extremely* expensive as it will, by
> default,
> build a giant OR clause consisting of every term in the field. You'll throw
> MaxClauses exceptions right and left. I'd follow Tim's thread lead first....
>
> Best
> Erick
>
> 2009/4/8 王巍巍 <ww.wang.cs@gmail.com>
>
>   
>> first you should change your querypaser to accept wildcard query by calling
>> method of QueryParser
>>          setAllowLeadingWildcard
>> then you can query like this:  fieldname:*
>>
>> 2009/4/9 Tim Williams <williamstw@gmail.com>
>>
>>     
>>> On Wed, Apr 8, 2009 at 11:45 AM, addman <addiekong@yahoo.com> wrote:
>>>       
>>>> Hi,
>>>>   Is it possible to create a query to search a field for any value?  I
>>>>         
>>> just
>>>       
>>>> need to know if the optional field contain any data at all.
>>>>         
>>> google for:  lucene field existence
>>>
>>> There's no way built in, one strategy[1] is to have a 'meta field'
>>> that contains the names of the fields the document contains.
>>>
>>> --tim
>>>
>>> [1] -
>>> http://www.mail-archive.com/lucene-user@jakarta.apache.org/msg07703.html
>>>
>>> ---------------------------------------------------------------------
>>> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
>>> For additional commands, e-mail: java-user-help@lucene.apache.org
>>>
>>>
>>>       
>> --
>> 王巍巍(Weiwei Wang)
>> Department of Computer Science
>> Gulou Campus of Nanjing University
>> Nanjing, P.R.China, 210093
>>
>> Mobile: 86-13913310569
>> MSN: ww.wang.cs@gmail.com
>> Homepage: http://cs.nju.edu.cn/rl/weiweiwang
>>
>>     
>
>   


-- 
Matthew Hall
Software Engineer
Mouse Genome Informatics
mhall@informatics.jax.org
(207) 288-6012



---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


Mime
View raw message