Solr ngram是否与数字不匹配？

Question

我使用标准的Solr ngram字段定义--

<fieldType name="ngram" class="solr.TextField" positionIncrementGap="100" stored="false" multiValued="true">
  <analyzer type="index">
    <tokenizer class="solr.StandardTokenizerFactory"/>
    <!-- potentially word delimiter, synonym filter, stop words, NOT stemming -->
    <filter class="solr.LowerCaseFilterFactory"/>
    <filter class="solr.NGramFilterFactory" minGramSize="2" maxGramSize="15"/>
  </analyzer>
  <analyzer type="query">
    <tokenizer class="solr.StandardTokenizerFactory"/>
    <!-- potentially word delimiter, synonym filter, stop words, NOT stemming -->
    <filter class="solr.LowerCaseFilterFactory"/>
  </analyzer>
</fieldType>

<field name="item" type="text" indexed="true" stored="true"/>
<field name="item_ngram" type="ngram" indexed="true" stored="true"/>

现在"item:ipad AND item:2“可以找到"iPad 2"，但是"item_ngram:ipad和item_ngram:2”不能。

有什么想法吗？

Answer 1

N-gram的最小长度为2 (minGramSize="2")。所以item_ngram:2不会匹配任何东西。将其减少到1，您将得到匹配结果。