André, See the thread "How to loop through all the entries for a field" in the October 2009 list archive which illustrates the method IndexReader.Terms. This is the optimum choice since your case is quite specific.
The thread "Alternative to looping through Hits", also in the October 2009 list archive, is germane to sorting in the general case. In my humble opinion the best way to learn is to get into the source, browse over the class documentation, and implement simple use tests. -----Original Message----- From: André Maldonado [mailto:andre.maldon...@gmail.com] Sent: Tuesday, November 03, 2009 11:29 AM To: lucene-net-user@incubator.apache.org Subject: Re: Simple question This thread is getting big... Franklin, I totally agree this approach can result in a problem, but I don't know yet how to do this search with TermEnum. What is the basic documentation to learn (I mean really learn, with all different query types) about queries? Thank's "Então aproximaram-se os que estavam no barco, e adoraram-no, dizendo: És verdadeiramente o Filho de Deus." (Mateus 14:33) On Tue, Nov 3, 2009 at 13:33, Franklin Simmons <fsimm...@sccmediaserver.com>wrote: > André, > > You can pass null for the filter parameter. TopDocCollector and > TopFieldDocCollector lets you limit hits. I have to say that while this > approach may seem OK with a very small index it will become a major problem > for you as index size grows, because MatchAllDocsQuery results in a sorting > of all documents in the index having the sort field. You should heed the > advice offered by Digy earlier in this discussion to use TermEnum. > > > -----Original Message----- > From: André Maldonado [mailto:andre.maldon...@gmail.com] > Sent: Tuesday, November 03, 2009 8:50 AM > To: lucene-net-user@incubator.apache.org > Subject: Re: Simple question > > When I do: > > Hits hits = searcher.Search(new *MatchAllDocsQuery()*, sort); > > The searcher return all documents. Can I return only the first 5 documents? > Like a TOP 5 in SQL Server? > > Probably using searcher.Search(Query query, Filter filter, int n, Sort > sort) > I can do it, but I don't have a filter.. > > How can I do it? > > Thank's > > > "Então aproximaram-se os que estavam no barco, e adoraram-no, dizendo: És > verdadeiramente o Filho de Deus." (Mateus 14:33) > > > 2009/11/3 André Maldonado <andre.maldon...@gmail.com> > > > Franklin, the error was exactly that. > > > > Some documents had a string where only an int can be. After made some > code > > adjustment, reindexing everything made it work. > > > > > > Thank's > > > > "Então aproximaram-se os que estavam no barco, e adoraram-no, dizendo: És > > verdadeiramente o Filho de Deus." (Mateus 14:33) > > > > > > On Fri, Oct 30, 2009 at 18:19, Franklin Simmons < > > fsimm...@sccmediaserver.com> wrote: > > > >> What type of data is represented by your field? > >> > >> There are any number of reasons why this could happen, such as using > >> SortField.INT on a field with terms having non-digit characters. > >> > >> Without knowing specifics, I can only offer that you try > SortField.STRING. > >> > >> -----Original Message----- > >> From: André Maldonado [mailto:andre.maldon...@gmail.com] > >> Sent: Friday, October 30, 2009 3:47 PM > >> To: lucene-net-user@incubator.apache.org > >> Subject: Re: Simple question > >> > >> Hi again Franklin. > >> > >> Sorry, but didn't work. I'm using Lucene.net 2.3 and doing exactly what > >> you > >> said, I'm getting this error: > >> > >> System.FormatException: Input string was not in correct format. > >> em System.Number.StringToNumber(String str, NumberStyles options, > >> NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) > >> em System.Number.ParseInt32(String s, NumberStyles style, > >> NumberFormatInfo info) > >> em > >> Lucene.Net.Search.FieldCacheImpl.AnonymousClassIntParser.ParseInt(String > >> value_Renamed) > >> em > >> > >> > Lucene.Net.Search.FieldCacheImpl.AnonymousClassCache2.CreateValue(IndexReader > >> reader, Object entryKey) > >> em Lucene.Net.Search.FieldCacheImpl.Cache.Get(IndexReader reader, > Object > >> key) > >> em Lucene.Net.Search.FieldCacheImpl.GetInts(IndexReader reader, String > >> field, IntParser parser) > >> em Lucene.Net.Search.FieldCacheImpl.GetInts(IndexReader reader, String > >> field) > >> em Lucene.Net.Search.FieldSortedHitQueue.ComparatorInt(IndexReader > >> reader, String fieldname) > >> em > >> > >> > Lucene.Net.Search.FieldSortedHitQueue.AnonymousClassCache.CreateValue(IndexReader > >> reader, Object entryKey) > >> em Lucene.Net.Search.FieldCacheImpl.Cache.Get(IndexReader reader, > Object > >> key) > >> em > Lucene.Net.Search.FieldSortedHitQueue.GetCachedComparator(IndexReader > >> reader, String field, Int32 type, CultureInfo locale, > SortComparatorSource > >> factory) > >> em Lucene.Net.Search.FieldSortedHitQueue..ctor(IndexReader reader, > >> SortField[] fields, Int32 size) > >> em Lucene.Net.Search.IndexSearcher.Search(Weight weight, Filter > filter, > >> Int32 nDocs, Sort sort) > >> em Lucene.Net.Search.Hits.GetMoreDocs(Int32 min) > >> em Lucene.Net.Search.Hits..ctor(Searcher s, Query q, Filter f, Sort o) > >> em Lucene.Net.Search.Searcher.Search(Query query, Sort sort) > >> em SearcherLibrary.Searcher.Search(String[] fields, String orderBy, > >> Int32 > >> type, Object analyzer) na > >> > c:\Maldonado\projetos\BuscaBlog\Indexer\SearcherLibrary\Searcher.cs:linha > >> 252 > >> em SearcherLibrary.Searcher.Search(String orderBy, sortType type, > Int32 > >> hitCount) na > >> > c:\Maldonado\projetos\BuscaBlog\Indexer\SearcherLibrary\Searcher.cs:linha > >> 313 > >> em IndexerConsole.Program.Main(String[] args) na > >> c:\Maldonado\projetos\BuscaBlog\Indexer\IndexerConsole\Program.cs:linha > 21 > >> > >> Any idea? > >> > >> Thank's > >> > >> "Então aproximaram-se os que estavam no barco, e adoraram-no, dizendo: > És > >> verdadeiramente o Filho de Deus." (Mateus 14:33) > >> > >> > >> On Fri, Oct 30, 2009 at 16:06, Franklin Simmons < > >> fsimm...@sccmediaserver.com > >> > wrote: > >> > >> > I did it again, think I'll hang it up for the day. The correct query > >> class > >> > name is 'MatchAllDocsQuery'. > >> > > >> > -----Original Message----- > >> > From: Franklin Simmons [mailto:fsimm...@sccmediaserver.com] > >> > Sent: Friday, October 30, 2009 2:06 PM > >> > To: lucene-net-user@incubator.apache.org > >> > Subject: RE: Simple question > >> > > >> > Oops, I'm not being very helpful. > >> > > >> > Use the MatchAllDocumentsQuery class: > >> > > >> > Searcher searcher = new IndexSearcher(directory); > >> > > >> > Sort = new Sort(new SortField("another_field", SortField.AUTO, > false)); > >> > > >> > Hits hits = searcher.search(new MatchAllDocumentsQuery(),sort); > >> > > >> > > >> > However, that may be a lot of processing. You may want to tune the > >> query > >> > in a way to minimize overhead; someone else in the list may suggest a > >> better > >> > strategy. > >> > > >> > > >> > -----Original Message----- > >> > From: Franklin Simmons [mailto:fsimm...@sccmediaserver.com] > >> > Sent: Friday, October 30, 2009 2:01 PM > >> > To: lucene-net-user@incubator.apache.org > >> > Subject: RE: Simple question > >> > > >> > Hi André, > >> > > >> > In this case you simply sort on the field. This may suffice: > >> > > >> > Searcher searcher = new IndexSearcher(directory); > >> > > >> > Sort = new Sort(new SortField("another_field", SortField.AUTO, > false)); > >> > > >> > Hits hits = searcher.search(query,sort); > >> > > >> > > >> > You can limit the number of hits (e.g. to 5), but I won't get into > that > >> > here. > >> > > >> > > >> > Beyond SortField.AUTO, take a look at the SortField class to see > >> specific > >> > field types - the most interesting being SortField.CUSTOM. > >> > > >> > > >> > -----Original Message----- > >> > From: André Maldonado [mailto:andre.maldon...@gmail.com] > >> > Sent: Friday, October 30, 2009 1:46 PM > >> > To: lucene-net-user@incubator.apache.org > >> > Subject: Re: Simple question > >> > > >> > Hi Franklin. > >> > > >> > Wich query I use for this search (variable: query)? I don't want any > >> query, > >> > I just want the TOP 5 documents ordered by a field. > >> > > >> > Thank's > >> > > >> > "Então aproximaram-se os que estavam no barco, e adoraram-no, dizendo: > >> És > >> > verdadeiramente o Filho de Deus." (Mateus 14:33) > >> > > >> > > >> > On Fri, Oct 30, 2009 at 15:03, Franklin Simmons < > >> > fsimm...@sccmediaserver.com > >> > > wrote: > >> > > >> > > You can sort a search by multiple fields. I think you could try > >> > something > >> > > like this: > >> > > > >> > > Searcher searcher = new IndexSearcher(directory); > >> > > Sort = new Sort(new SortField[] { SortField.FIELD_SCORE, new > >> > > SortField("another_field") }; > >> > > Hits hits = searcher.search(query,sort); > >> > > > >> > > > >> > > -----Original Message----- > >> > > From: André Maldonado [mailto:andre.maldon...@gmail.com] > >> > > Sent: Friday, October 30, 2009 12:57 PM > >> > > To: lucene-net-user@incubator.apache.org > >> > > Subject: Simple question > >> > > > >> > > Hi. > >> > > > >> > > This can be a simple question, but I can't figure out the solution. > >> > > > >> > > I need to search my index in something like "SELECT TOP 5 ... ORDER > BY > >> > > another_field". But this is an empty query because I want to search > in > >> > all > >> > > documents. > >> > > > >> > > How can I do it? > >> > > > >> > > Thank's > >> > > > >> > > >> > > > > >
