GroupBy clause for both search providers (Solr, Azure)

Question

Would like to use groupby clause in Sitecore 9.1.1 for both search provide (Azure, Solr) in content search API. However, Sitecore does not support this clause. Kindly let us know how we can group result based on common categories so it would work on both (Solr and Azure) search provider.

Answer 1

Categorizing can be achieved with faceting, using the FacetOn method. Official documentation can be found here.

Simple faceting

var results = queryable.FacetOn(d => d.Name); 
var facets = results.GetFacets(); 
foreach (var category in facets.Categories) { 
    Console.WriteLine(category.Name); 
    foreach (var facetValue in category.Values) { 
        Console.WriteLine("{0}: {1}", facetValue.Name, facetValue.Aggregate); 
    } 
}

With the code above, you can get the facets which are used by your items. facetValue.Name is the Guid of the items, so based on this you can get the items from Sitecore to show additional data from the item.