ElasticSearch NEST词条查询未返回任何结果

Z时代
2024-01-10
分类：问答

这是我的架构

[ElasticType(Name = "importFile")]
public class ImportFile : DocumentMapping
{
    [ElasticProperty(Store = false, Index = FieldIndexOption.NotAnalyzed)]
    public string FileName { get; set; }
    [ElasticProperty(Store = false, Index = FieldIndexOption.NotAnalyzed)]
    public string GroupId { get; set; }
    [ElasticProperty(Store = false, Index = FieldIndexOption.Analyzed)]
    public string FilePath { get; set; }
}

我做了这样的一个NEST查询：

    var res = ElasticClient.Search<ImportFile>(s => s
        .Index(ElasticIndexName)
        .Filter(f =>
            f.Term(t => t.FileName, "Group-1.uhh"))).Documents.ToArray();

并返回零元素！

如果我查看数据库（使用邮递员），则可以看到我的文档：

{ "took": 5, "timed_out": false, "_shards": { "total": 2, "successful": 2, "failed": 0 }, "hits": { "total": 2, "max_score": 14.069489, "hits": [ { "_index": "reviewer-bdd-test-index", "_type": "importFile", "_id": "AU9kUka2hr5Jg98UXOae", "_score": 14.069489, "_source": { "fileName": "Group-1.uhh", "groupId": "0ae1206d0644eabd82ae490e612732df5da2cd141fdee70dc64207f86c96094f", "filePath": "" } }, { "_index": "reviewer-bdd-test-index", "_type": "importFile", "_id": "AU9kZO25hr5Jg98UXRnk", "_score": 14.069489, "_source": { "fileName": "group-1.uhh", "groupId": "0ae1206d0644eabd82ae490e612732df5da2cd141fdee70dc64207f86c96094f", "filePath": "" } } ] } }

回答：

听起来您可能没有在为文档建立索引之前

将类型的映射显式地放入索引中，所以Elasticsearch已基于所看到文档中字段的默认映射来推断该映射。例如，给定以下类型

[ElasticType(Name = "importFile")]
public class ImportFile
{
    [ElasticProperty(Store = false, Index = FieldIndexOption.NotAnalyzed)]
    public string FileName { get; set; }
    [ElasticProperty(Store = false, Index = FieldIndexOption.NotAnalyzed)]
    public string GroupId { get; set; }
    [ElasticProperty(Store = true, Index = FieldIndexOption.Analyzed)]
    public string FilePath { get; set; }
}

如果我们按以下方式索引一些文档

void Main()
{
    var settings = new ConnectionSettings(new Uri("http://localhost:9200"));            
    var client = new ElasticClient(settings);
    client.Index<ImportFile>(
        new ImportFile{
            FileName = "Group-1.uhh",
            FilePath = "",
            GroupId = "0ae1206d0644eabd82ae490e612732df" + 
                      "5da2cd141fdee70dc64207f86c96094"
        },
        index => index
            .Index("reviewer-bdd-test-index")
            .Type("importFile")
            .Refresh());
    client.Index<ImportFile>(
        new ImportFile
        {
            FileName = "group-1.uhh",
            FilePath = "",
            GroupId = "0ae1206d0644eabd82ae490e612732df" + 
                      "5da2cd141fdee70dc64207f86c96094"
        },
        index => index
            .Index("reviewer-bdd-test-index")
            .Type("importFile")
            .Refresh());
    var results = client.Search<ImportFile>(s => s
                .Index("reviewer-bdd-test-index")
                .Type("importFile")
                .Query(q => q
                   .Filtered(fq => fq
                        .Filter(f => f
                            .Term(p => p.FileName, "Group-1.uhh")
                        )
                    )
                )
            );
    Console.WriteLine(string.Format("{0} {1}", results.RequestInformation.RequestMethod, results.RequestInformation.RequestUrl));
    Console.WriteLine(Encoding.UTF8.GetString(results.RequestInformation.Request)); 
    Console.WriteLine("Matching document count: {0}", results.Documents.Count());
}

在控制台中输出以下内容

POST http://localhost:9200/reviewer-bdd-test-index/importFile/_search
{
  "query": {
    "filtered": {
      "filter": {
        "term": {
          "fileName": "Group-1.uhh"
        }
      }
    }
  }
}
Matching document count: 0

我们没有匹配的文件。在Elasticsearch中检查映射

curl -XGET "http://localhost:9200/reviewer-bdd-test-index/_mapping"

我们看到类型的映射importFile是

{
   "reviewer-bdd-test-index": {
      "mappings": {
         "importFile": {
            "properties": {
               "fileName": {
                  "type": "string"
               },
               "groupId": {
                  "type": "string"
               }
            }
         }
      }
   }
}

这不是我们所期望的；fileName和两者groupId都应有"index":

"not_analyzed"，filePath甚至不在映射中。这两个都是因为Elasticsearch已根据传递的文档推断了映射-

fileName并groupId已映射为字符串类型并且将使用标准分析器进行分析，并且 我相信

filePath尚未映射，因为两个看到的文档都为空字段的字符串值，因此应用于该字段的

不会为倒排索引生成任何标记，因此该字段不包含在映射中。

因此，为了确保一切正常，我们需要在索引任何文档之前向索引添加一个映射

void Main()
{
    var settings = new ConnectionSettings(new Uri("http://localhost:9200"));
    var client = new ElasticClient(settings);
    // Add the mapping for ImportFile to the index
    client.CreateIndex(indexSelector => indexSelector
        .Index("reviewer-bdd-test-index")
        .AddMapping<ImportFile>(mapping => mapping
            .MapFromAttributes()
        )
    );
    // ... Same as above after this point
}

导致

POST http://localhost:9200/reviewer-bdd-test-index/importFile/_search
{
  "query": {
    "filtered": {
      "filter": {
        "term": {
          "fileName": "Group-1.uhh"
        }
      }
    }
  }
}
Matching document count: 1

我们有一个匹配的文件。检查Elasticsearch中的映射会产生我们期望的结果

{
   "reviewer-bdd-test-index": {
      "mappings": {
         "importFile": {
            "properties": {
               "fileName": {
                  "type": "string",
                  "index": "not_analyzed"
               },
               "filePath": {
                  "type": "string",
                  "store": true
               },
               "groupId": {
                  "type": "string",
                  "index": "not_analyzed"
               }
            }
         }
      }
   }
}

此外，可以将属性映射替换为流畅的映射

var indexResult = client.CreateIndex(indexDescriptor => indexDescriptor
    .Index("reviewer-bdd-test-index")
    .AddMapping<ImportFile>(mapping => mapping
        .Type("importFile")
        .MapFromAttributes()
        .Properties(properties => properties
            .String(s => s
                .Name(file => file.FileName)
                .Store(false)
                .Index(FieldIndexOption.NotAnalyzed))
            .String(s => s
                .Name(file => file.GroupId)
                .Store(false)
                .Index(FieldIndexOption.NotAnalyzed))
            .String(s => s
                .Name(file => file.FilePath)
                .Store(true))
        )
    )
);