Number of times the term appears in the field in SOLR

This blog represents how to get the total number of times a particular term exists in a field in while searching from solr.

Suppose you have an index and have populated some document in the index , and in the documents , you have a field _content , which is of text_general type , and from that field you want to search a term immigration .

To search immigration , in the Solr Admin , write the query
 q=_content:("immigration")  and execute the query , but if you also want to sort the results on the basis of relevancy , that how often that term appears in the document , then you have to use
termfreq  function.

Syntax Examples :- 
termfreq(fieldname,'term')

To achieve that , in the sort field in solr admin , write

termfreq("_content","immigration") desc (for descending)

and in the fl field write

_displayname,termfreq(_content,"immigration") desc

 to show the Display Name of each document and also the number of hits of the keyword immigration in each field .

Solr sorts the results based on the relevancy of the term present in the field OOTB (it uses tf-idf algorithm to calculate scoring).

How to achieve this programatically -

using (var context = ContentSearchManager.GetIndex("contentIndex").CreateSearchContext(SearchSecurityOptions.DisableSecurityCheck))

                {
var queryableResultItems = context.GetQueryable<GlobalSearchResultItem >()
                    .Where(expression)

                  .OrderByDescending(x => x["termfreq(_content," + text.Trim() + ")"]);
}

Note -  

Your field on which you want to perform search operations should be tokenized .