SolrQuery::addGroupFunction Allows grouping results based on the unique values of a function query (group.func parameter). &reftitle.description; public SolrQuerySolrQuery::addGroupFunction stringvalue Adds a group function (group.func parameter) Allows grouping results based on the unique values of a function query. &reftitle.parameters; value &reftitle.returnvalues; SolrQuery &reftitle.seealso; SolrQuery::setGroup SolrQuery::addGroupField SolrQuery::addGroupQuery SolrQuery::addGroupSortField SolrQuery::setGroupFacet SolrQuery::setGroupOffset SolrQuery::setGroupLimit SolrQuery::setGroupMain SolrQuery::setGroupNGroups SolrQuery::setGroupTruncate SolrQuery::setGroupFormat SolrQuery::setGroupCachePercent