Use the TermFreq() function programatically in Sitecore

Question

I was building query on the basis of the occurence/relevancy of the terms present in a field and got one issue , suppose i searched for a keyword "text" in the content field , and i want to sort the results on the basis of the relevancy of the term present in the field , for ex , if that keyword is present more times then that document will be listed on the top . here is my code

 var queryableResultItems = context.GetQueryable<GlobalSearchResultItem>()
              .Where(x => x.Language.Equals(Sitecore.Context.Language.Name, StringComparison.InvariantCultureIgnoreCase)).Where(UseSearchComponents.GetTemplatesFilterPredicate(Guid.Parse(TemplateConstants.BlogPreviewTemplate))).Where(UseSearchComponents.GetSearchFilters(keyword, searchType)).Skip((Int32.Parse(pagenumber) - 1) * 12).Take(12).GetResults();


 public static Expression<Func<GlobalSearchResultItem , bool>> GetSearchFilters(string Keyword,string searchType)
    {
        Expression<Func<GlobalSearchResultItem, bool>> filterSearch = x => true;
        if(Keyword.IsTrimmedNullOrEmpty() || searchType.IsTrimmedNullOrEmpty())
        {
            return filterSearch;
        }
        Expression<Func<GlobalSearchResultItem, bool>> filterSearchText = x => true;
        if (!string.IsNullOrEmpty(Keyword) && searchType=="exactly")
        {    
            filterSearchText = filterSearchText.Or(x => x.Content.Contains(Keyword));
            filterSearch = filterSearch.And(filterSearchText);
        }
        if(!string.IsNullOrEmpty(Keyword) && searchType == "allwords")
        {
            float slop = 1000000;
            filterSearchText = filterSearchText.Or(x => x.Content.Like(Keyword,slop));
            filterSearch = filterSearch.And(filterSearchText);
        }
        return filterSearch;
    }
}

and then i used the termfreq("content_t","text") desc function in the solr console , but i don`t know how to do it programatically in solr using the contentsearch api. Some help would be apppreciated. Thanks in advance.

Answer 1

You can do it with:

var queryableResultItems = context.GetQueryable<GlobalSearchResultItem >()
                    .Where(expression)
                    .OrderByDescending(x => x["termfreq(content_t, \""+ term+ "\")"])

But I suggest you to setup logic that you need on Solr side. Sorl sorts the results based on the relevancy of the term present in the field OOTB (it uses tf-idf algorithm to calculate scoring).

You should check query analizer of your field type in managed-schema (your field should be tokenized):

<analyzer type="query">
      <tokenizer class="solr.WhitespaceTokenizerFactory"/>
      ...
    </analyzer>

You can check it in Solr by adding "score" in fl textbox. You can also see how scoring is calculating by checking debugQuery:

As you can see, Solr uses termFreq OOTB while scoring: