Phalcon\Db\Adapter\MongoDB\Collection::createIndex PHP Method

Create a single index for the collection.

See also: Collection::createIndexes()

public createIndex ( array \| object $key, array $options = [] ) : string
$key	array \| object	Document containing fields mapped to values, which denote order or an index type
$options	array	Index options
return	string	The name of the created index

    public function createIndex($key, array $options = [])
    {
        return current($this->createIndexes([['key' => $key] + $options]));
    }

Collection