how to use "find" to search "_id => OBjectID("id")" in Perl API
In reading the MongoDB::Tutorial
use MongoDB loads most of the packages you'll need to interact with MongoDB: MongoDB::Connection, MongoDB::Database, MongoDB::Collection, and MongoDB::Cursor. To use special Mongo data types (see MongoDB::DataTypes), you have to include them separately. So, usually, to use Mongo, you'll start with at least:
use MongoDB;use MongoDB::OID;Then you can just do this in your code:
$db->$collection->find_one({ _id => $id })