MongoCollection::toIndexString Converts keys specifying an index to its identifying string &reftitle.description; static protected stringMongoCollection::toIndexString mixedkeys &reftitle.parameters; keys Field or fields to convert to the identifying string &reftitle.returnvalues; Returns a string that describes the index. &reftitle.examples; This example shows how you can create an index name out of of keys. Because this is a protected (static) method, you need to overload it in a child class first. 1, 'age' => -1)), "\n"; // Outputs: name_1_age_-1 ?> ]]> &reftitle.seealso; MongoDB core docs on indexes.