Solr search with stemming

Question

We are running Sitecore 8.0 and Solr 4.10.3. I'm trying to get text search working where if I search for play, player and plays are also returned in the search results.

I can't find reference on how to achieve this. The current search that I have configured just does a straight text lookup and only returns results with play.

Do I need to create a analyzer in Solr with one of the stemming algorithms to achieve this?

I'm using the contains function to run the text search in Sitecore search api.

Answer 1

You can do this on the SOLR configuration site. To setup stemming in SOLR you just need to set the tokenizer and analyzer for the field.

For example. Say you have a field in your template called Body Text - rather than use the dynamic SOLR field, you can add this to your schema.xml.

<field name="body_text" type="text_stem" indexed="true" stored="true" multiValued="true"/>

Now we just need to define the field type in the schema and set the tokenizer and filter:

<fieldType name="text_stem">
    <analyzer>
        <tokenizer class="solr.WhitespaceTokenizerFactory"/>
        <filter class="solr.SnowballPorterFilterFactory"/>
    </analyzer>
</fieldType>

What do these do:

• solr.WhitespaceTokenizerFactory - this will break up the sentences into words using whitespace as the delimeter
• solr.SnowballPorterFilterFactory - will apply a stemming algorithm to each work or token. There are a number of stemming algorithms, this example uses the Snowball Porter one.

For more examples look at Keyword Stemming and Lemmatisation with SOLR

Answer 2

Sure, you could use stemming. But as the simplest approach, you can go with a wildcard query:

using (IProviderSearchContext context = ...)
{
  var searchTerm = "play";

  var query =
    context.GetQueryable<SearchResultItem>()
      .Where(_ => _.FieldName.MatchWildcard(searchTerm + "*"));

  SearchResults<SearchResultItem> results = query.GetResults();
}

Make sure to sanitize the search term beforehand.