(PECL solr >= 0.9.2)
SolrDocument::merge — Merges source to the current SolrDocument
Merges source to the current SolrDocument.
sourceDoc
The source document.
overwrite
If this is TRUE
then fields with the same name in the destination document will be overwritten.
Restituisce TRUE
in caso di successo, FALSE
in caso di fallimento.