嗨，NEST的作者在这里，
如果您使用注释，则需要手动调用
var createIndex = client.CreateIndex("default_index", new IndexSettings { });client.Map<Movie>();在第一次调用索引之前。
Nest不会将映射应用于每个索引调用，因为这会产生过多的开销。如果弹性索引的旧版本不存在并且不需要
CreateIndex调用，则只会创建该索引。
由于您想使用嵌套类型，因此必须传递
.Nested("genres")给facet调用。您看到的数字实际上是嵌套的docid ：)
这是我修改后的program.cs，可以正常工作：
using System;using System.Collections.Generic;using System.Linq;using Nest;namespace Demo{ class Program { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Description { get; set; } [ElasticProperty(Type=FieldType.nested)] public List<Genre> Genres { get; set; } public int Year { get; set; } } public class Genre { // public int Id { get; set; } [ElasticProperty(Index = FieldIndexOption.not_analyzed)] public string GenreTitle { get; set; } } static void Main(string[] args) { var setting = new ConnectionSettings("localhost", 9200); setting.SetDefaultIndex("default_index"); var client = new ElasticClient(setting); // delete previous index with documents client.DeleteIndex<Movie>(); var createIndexResult = client.CreateIndex("default_index", new IndexSettings { }); var mapResult = client.Map<Movie>(); // put documents to the index var genres = new List<Genre>(); for (var i = 0; i < 100; i++) genres.Add(new Genre { GenreTitle = string.Format("Genre {0}", i) }); for (var i = 0; i < 1000; i++) { client.Index(new Movie { Id = i, Description = string.Format("Some movie description {0}", i), Title = string.Format("Movie Title {0}", i), Year = 1980 + (i % 10), Genres = genres.OrderBy(x => Guid.NewGuid()).Take(10).ToList() }); } // query with facet on nested field property genres.genreTitle var queryResults = client.Search<Movie>(x => x .From(0) .Size(10) .MatchAll() .FacetTerm(t => t .onField(f => f.Year) .Size(30)) .FacetTerm(t => t .Size(5) .onField(f => f.Genres.Select(f1 => f1.GenreTitle)) .Nested("genres") ) ); var yearFacetItems = queryResults.FacetItems<FacetItem>(p => p.Year); foreach (var item in yearFacetItems) { var termItem = item as TermItem; Console.WriteLine(string.Format("{0} ({1})", termItem.Term, termItem.Count)); } var genresFacetItems = queryResults.FacetItems<FacetItem>(p => p.Genres.Select(f => f.GenreTitle)); foreach (var item in genresFacetItems) { var termItem = item as TermItem; Console.WriteLine(string.Format("{0} ({1})", termItem.Term, termItem.Count)); } } }}
