Faceting by field counts the number of occurrences of a term in a specific field. Let us create facets on author and genre. There are separate string fields in our Solr index for indexing facet-related strings without any tokenization. In this case, the fields are author_s and genre_s.
Note
Fields ending with _s are dynamic fields defined in our Solr schema.xml. Dynamic fields defined as *_s match any field that ends in _s and all attributes in the field definition are applied on this field.
To create a facet on our author_s field, we need to get the facetset component from the Solarium query, create a facet field key and set the actual field using the facets that will be created.
$query->setQuery('cat:book');
$facetset = $query->getFacetSet();
$facetset->createFacetField('author')->setField('author_s');Set the number of facets to get using the following code:
$facetset->setLimit(5);
Return all facets that have at least one term in them.
$facetset->setMinCount...