休眠搜索 |具有 minGramSize 1 的 ngram 分析器 [英] Hibernate Search | ngram analyzer with minGramSize 1

问题描述

我的 Hibernate Search 分析器配置存在一些问题.我的索引实体之一(医院")有一个字符串字段(名称")，它可以包含长度为 1-40 的值.我希望能够通过仅搜索一个字符来找到一个实体(因为医院可能有单个字符名称).

I have some problems with my Hibernate Search analyzer configuration. One of my indexed entities ("Hospital") has a String field ("name") that could contain values with lengths from 1-40. I want to be able to find a entity by searching for just one character (because it could be possible, that a hospital has single character name).

@Indexed(index = "HospitalIndex")
@AnalyzerDef(name = "ngram",
        tokenizer = @TokenizerDef(factory = StandardTokenizerFactory.class),
        filters = {
                @TokenFilterDef(factory = StandardFilterFactory.class),
                @TokenFilterDef(factory = LowerCaseFilterFactory.class),
                @TokenFilterDef(factory = NGramFilterFactory.class,
                        params = {
                                @Parameter(name = "minGramSize", value = "1"),
                                @Parameter(name = "maxGramSize", value = "40")})
        })
public class Hospital {

        @Field(index = Index.YES, analyze = Analyze.YES, store = Store.NO, analyzer = @Analyzer(definition = "ngram"))
        private String name = "";
}

如果我添加一个名为我的测试医院"的医院，Lucene 索引如下所示:

If I add a hospital with name "My Test Hospital" the Lucene index looks like this:

1   name    al
1   name    e
1   name    es
1   name    est
1   name    h
1   name    ho
1   name    hos
1   name    hosp
1   name    hospi
1   name    hospit
1   name    hospita
1   name    hospital
1   name    i
1   name    it
1   name    ita
1   name    ital
1   name    l
1   name    m
1   name    my
1   name    o
1   name    os
1   name    osp
1   name    ospi
1   name    ospit
1   name    ospita
1   name    ospital
1   name    p
1   name    pi
1   name    pit
1   name    pita
1   name    pital
1   name    s
1   name    sp
1   name    spi
1   name    spit
1   name    spita
1   name    spital
1   name    st
1   name    t
1   name    ta
1   name    tal
1   name    te
1   name    tes
1   name    test
1   name    y
1   name    a

这就是我构建和执行搜索查询的方式:

This is how I build and execute my search query:

QueryBuilder hospitalQb = fullTextEntityManager.getSearchFactory().buildQueryBuilder().forEntity(Hospital.class).get();
Query hospitalQuery = hospitalQb.keyword().onFields("name")().matching(searchString).createQuery();
javax.persistence.Query persistenceQuery = fullTextEntityManager.createFullTextQuery(hospitalQuery, Hospital.class);
List<Hospital> results = persistenceQuery.getResultList();  

问题是我的搜索查询也使用了相同的 ngram 分析器.因此，当我搜索医院"时，我会找到名称中包含a"字符的所有医院.这是搜索查询的样子，当我在其上调用 toString 方法时:

The problem is that the same ngram analyzer is also used for my search query. So when I am search for example for "hospital" I will find all hospitals that contains a "a"-character in the name. This is how the search query looks likes, when I call the toString method on it:

name:h name:ho name:hos name:hosp name:hospi name:hospit name:hospita name:hospital name:o name:os name:osp name:ospi name:ospit name:ospita name:ospital name:s name:sp name:spi name:spit name:spita name:spital name:p name:pi name:pit name:pita name:pital name:i name:it name:ita name:ital name:t name:ta name:tal name:a name:al name:l

所以问题是，是否有人知道更好的分析器配置或其他方式构建解决问题的搜索查询?

So the question is, does anybody know a better analyzer configuration or another way build the search query that solves the problem?

推荐答案

您可以设置第二个分析器，除了没有 ngram 过滤器外，其他相同，然后覆盖用于查询的分析器:

You can set up a second analyzer, identical except that it does not have an ngram filter, and then override the analyzer used for queries:

QueryBuilder hospitalQb = fullTextEntityManager.getSearchFactory().buildQueryBuilder().forEntity(Hospital.class)
    .overridesForField( "name", "my_analyzer_without_ngrams" )
    .get();
// Then it's business as usual

<小时>

此外，如果您要实现某种自动完成功能 (foo*)，而不是字内搜索 (*foo*)，您可能需要使用 EdgeNGramFilterFactory 而不是 NGramFilterFactory:它只会生成作为索引标记前缀的 ngram.

---

Additionally, if you are implementing some kind of auto-completion (foo*), and not in-word search (*foo*), you may want to use EdgeNGramFilterFactory instead of NGramFilterFactory: it will only generate ngrams that are prefixes of the indexed tokens.

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