c# - 使用 Nest Elastic 根据术语中的单词数进行搜索

Question

我有一个电子商务网站。用户可以搜索产品。每个产品都有“名称”、“品牌”、“类别”列表。 如果用户搜索“Tommy t-shirt men”，则仅应返回 mens tommy T-shirts 作为结果，不应返回包含单个单词 tommy 或 t-shirt 的结果。如果用户搜索“Tommy”，则应返回所有包含单词 tommy 的结果。如果用户搜索“Tommy men”，则仅应返回 tommy mens 产品，而不是单个匹配词 tommy 或单个匹配词 men。

我的代码看起来像这样:

public ISearchResponse<Models.Product> Search(string term, int minMatch)
{
    var response = client.Search<Models.Product>(search => search
            .Query(q => q.Bool(b => b.Should(
            s => s.Match(m => m.Query(term).Field(f => f.ProductName).Boost(5).Fuzziness(Fuzziness.EditDistance(0))),
            s => s.Match(m => m.Query(term).Field(f => f.Brand).Boost(15).Fuzziness(Fuzziness.EditDistance(0))),
            s => s.Match(m => m.Query(term).Field(f => f.Category).Boost(10).Fuzziness(Fuzziness.EditDistance(0)))
            ).MinimumShouldMatch(minMatch))));

            return response;
}

public ISearchResponse<Models.Product> Read(string term)
{
    var fixedInput = Regex.Split(term, @"[^\p{L}]*\p{Z}[^\p{L}]*");
    int minMatch;

    if (fixedInput.Count() > 1) minMatch = 2; 
    else  minMatch = 1; 

    var results = Search(term, minMatch);

    if (!results.Documents.Any() && minMatch.Equals(2))
    {
        results = Search(term, 1);
    }

    return results;
}

如果我搜索“Tommy men”，第一个结果是“Tommy men”，但其他结果是“Diesel men”、“Boss men”，如果搜索词有多个，如何过滤出一个单词匹配的结果词。

Answer 1

您的意思是下面这句话中的“tommy”!=“Tommy”吗？

no results with single word tommy or t-shirt should be returned. If user searching for "Tommy" then all results with word tommy should be returned.

对于其余示例，您可以使用 multi-match query与 cross_fields类型。

示例应用程序:

    public class Document
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Brand { get; set; }
        public string Category { get; set; }

        public override string ToString() => $"Id: {Id} Name: {Name} Brand: {Brand} Category: {Category}";
    }

    static async Task Main(string[] args)
    {
        var pool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));
        var connectionSettings = new ConnectionSettings(pool);
        connectionSettings.DefaultIndex("documents");

        var client = new ElasticClient(connectionSettings);

        var deleteIndexResponse = await client.Indices.DeleteAsync("documents");
        var createIndexResponse = await client.Indices.CreateAsync("documents", d => d
            .Map(m => m.AutoMap<Document>()));

        var indexDocument = await client
            .IndexDocumentAsync(new Document {Id = 1, Brand = "Tommy", Category = "men"});
        var indexDocument2 = await client
            .IndexDocumentAsync(new Document {Id = 2, Brand = "Diesel", Category = "men"});
        var indexDocument3 = await client
            .IndexDocumentAsync(new Document {Id = 3, Brand = "Boss", Category = "men"});

        var refreshAsync = client.Indices.RefreshAsync();

        var query = "Tommy";
        var searchResponse = await Search(client, query);
        PrintResults(query, searchResponse);

        query = "Tommy men";
        searchResponse = await Search(client, query);
        PrintResults(query, searchResponse);

        query = "men";
        searchResponse = await Search(client, query);
        PrintResults(query, searchResponse);
    }

    private static async Task<ISearchResponse<Document>> Search(ElasticClient client, string query)
    {
        var searchResponse = await client.SearchAsync<Document>(s => s.Query(q => q
            .MultiMatch(mm => mm
                .Fields(f => f.Fields(ff => ff.Brand, ff => ff.Category, ff => ff.Name))
                .Query(query)
                .Type(TextQueryType.CrossFields)
                .MinimumShouldMatch("100%"))));
        return searchResponse;
    }

    private static void PrintResults(string query, ISearchResponse<Document> searchResponse)
    {
        Console.WriteLine($"query: {query}");
        Console.WriteLine(searchResponse.Total);
        Console.WriteLine($"results: ");
        searchResponse.Documents.ToList().ForEach(Console.WriteLine);
        Console.WriteLine();
    }
}

打印:

query: Tommy
found: 1
Id: 1 Name:  Brand: Tommy Category: men

query: Tommy men
found: 1
Id: 1 Name:  Brand: Tommy Category: men

query: men
found: 3
Id: 1 Name:  Brand: Tommy Category: men
Id: 2 Name:  Brand: Diesel Category: men
Id: 3 Name:  Brand: Boss Category: men

希望有帮助。