如何使用 Mpdreamz/NEST Elasticsearch 客户端根据嵌套字段的属性列出构面?
我检查了 Nest 文档,但不清楚如何去做。
这是我试过的代码:
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(Index = FieldIndexOption.analyzed, 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.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>();
// 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) )
)
);
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));
}
/* Returns:
1989 (90)
1988 (90)
1986 (90)
1984 (90)
1983 (90)
1981 (90)
1980 (90)
1987 (89)
1982 (89)
1985 (88)
and it's fine! */
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));
}
/* Return soemthing:
genre (842)
98 (47)
51 (30)
24 (29)
46 (28)
and it's BAD!
I expect the Genre Title to be listed as
string, not as some strange integer */
}
}
}
作为方面的结果,我得到:
虽然我希望得到类似的东西:
我做错了什么?在哪里检查在 Nest 中使用嵌套字段的正确方法以及它们的方面?
谢谢你。
更新 1:
我发现它与标记器/分析器有关。如果流派名称没有空格或破折号 - 一切正常。
我也试过未分析的索引属性
[ElasticProperty(Index = FieldIndexOption.not_analyzed)]
public string GenreTitle { get; set; }
但它没有帮助
更新 2:
我在之前的索引删除后立即添加了流畅的索引映射而不是注释,例如:
var settings = new IndexSettings();
var typeMapping = new TypeMapping("movies");
var type = new TypeMappingProperty
{
Type = "string",
Index = "not_analyzed",
Boost = 2.0
// Many more options available
};
typeMapping.Properties = new Dictionary<string, TypeMappingProperty>();
typeMapping.Properties.Add("genres.genreTitle", type);
settings.Mappings.Add(typeMapping);
client.CreateIndex("default_index", settings);
现在不确定注释有什么问题。使用注释进行索引设置是否需要任何其他配置?
最佳答案
嗨,这里的 NEST 作者,
如果使用注释,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
不会在每个索引调用上应用映射,因为这会导致过多的开销。如果索引不存在并且不需要 CreateIndex
调用,则旧版本的 elasticsearch 只会创建索引。由于您想对嵌套类型进行分面,因此必须将
.Nested("genres")
传递给分面调用。你看到的数字实际上是嵌套的 docids :)
这是我修改后的 program.cs 有效:
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));
}
}
}
}
关于elasticsearch - 带有 Elasticsearch C# Mpdreamz/NEST 客户端的嵌套字段的 Facet,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/13218346/