NGramAnalyzer is not working

[Nima Ha]

I wrote a test just like  this gist but it returns nothing . Here's the test :

[Fact]

        public void NGramAnalyzerTest()

        {

            using (var store = NewDocumentStore(runInMemory:false,dataDir:"Data"))

            {

                var p1 = new Person { Age = 18, Name = "John" };

                var p2 = new Person { Age = 21, Name = "Joe" };

                var p3 = new Person { Age = 27, Name = "Andy" };

                var p4 = new Person { Age = 31, Name = "Linda" };

                var p5 = new Person { Age = 45, Name = "Laura"};

                using (var session = store.OpenSession())

                {

                    session.Store(p1);

                    session.Store(p2);

                    session.Store(p3);

                    session.Store(p4);

                    session.Store(p5);

                    session.SaveChanges();

                }

                store.DatabaseCommands.PutIndex("PersonByName", new IndexDefinition

                {

                    Map = "from person in docs.Persons select new { person.Name }",

                    Indexes = {{"Name", FieldIndexing.Analyzed}},

                    Analyzers = { { "Name", typeof(NGramAnalyzer).AssemblyQualifiedName } }

                },true);

                using (var session = store.OpenSession())

                {

                    var query =

                        session.Query<Person>("PersonByName")

                            .Customize(x => x.WaitForNonStaleResults())

                            .OrderBy(p=>p.Name)

                            .Search(p => p.Name, "lin");

                    Assert.Equal(1,query.ToList().Count);

                }

                

            }

        }

I am expecting that this query will find "Linda" for me.

[Itamar Syn-Hershko]

The NGram analyzer is probably configured for a gram size of != 3, for this use case you want to use a prefix query and a normal word-boundary analyzer

--

Itamar Syn-Hershko

http://code972.com | @synhershko

Freelance Developer & Consultant

Author of RavenDB in Action

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[Nima Ha]

I am a new comer to Lucene .

Would you please be more specific. Here's what I actually want to . We have some documents that have addresses  I want to be able to perform a full-text search on these addresses ( with partial and complete words) how I can achieve this using Lucene ? 

Thanks a lot 

[Itamar Syn-Hershko]

You only need NGrams if you want to do partial word matches, but for your use case it is sufficient to use prefix matches. Use StandardAnalyzer and issue a prefix query using a wildcard, e.g. FieldName:lin*

--

Itamar Syn-Hershko

http://code972.com | @synhershko

Freelance Developer & Consultant

Author of RavenDB in Action

--

[Nima Ha]

OK I changed the code as follow :

using (var store = NewDocumentStore(runInMemory:false,dataDir:"Data"))

            {

                var p1 = new Person { Age = 12, Name = "John" };

                var p2 = new Person { Age = 16, Name = "Joe" };

                var p3 = new Person { Age = 7, Name = "Andy" };

                var p4 = new Person { Age = 11, Name = "Linda" };

                var p5 = new Person { Age = 5, Name = "Laura"};

                using (var session = store.OpenSession())

                {

                    session.Store(p1);

                    session.Store(p2);

                    session.Store(p3);

                    session.Store(p4);

                    session.Store(p5);

                    session.SaveChanges();

                }

                store.DatabaseCommands.PutIndex("PersonByName", new IndexDefinition

                {

                    Map = "from person in docs.Persons select new { person.Name }",

                    Indexes = {{"Name", FieldIndexing.Analyzed}},

                    Analyzers = { { "Name", typeof(StandardAnalyzer).AssemblyQualifiedName } }

                },true);

                using (var session = store.OpenSession())

                {

                    var query =

                        session.Query<Person>("PersonByName")

                            .Customize(x => x.WaitForNonStaleResults())

                            .OrderBy(p=>p.Name)

                            .Search(p => p.Name, "Li*",escapeQueryOptions: EscapeQueryOptions.AllowPostfixWildcard);

                    Assert.Equal(1,query.ToList().Count);

                }

                

            }

As you can see I am using StandardAnalyzer and "Li*" and also I use EscapeQueryOptions.AllowPostfixWildcard to tell Lucene not to escape the postfix wild card but still I am getting no results ??? whay can possibly be wrong with my code ?

[Oren Eini (Ayende Rahien)]

 docs.Persons 

Should be:

docs.People

Oren Eini

CEO

Mobile: + 972-52-548-6969

Office:  + 972-4-622-7811

Fax:      + 972-153-4622-7811

--

[Nima Ha]

Thanks :) looks like RavenDB is smarter than me ;)