1.连接MongoDB数据库（在已安装php-mongodb扩展的前提下）

$config = "mongodb://{$user}:{$pass}@{$host}:{$port}";$mongodb = new \MongoDB\Driver\Manager($config );

2.简单统计

$command = new \MongoDB\Driver\Command(['count' => $collection,'query'=>$filter]);$result = $mongodb->executeCommand($db,$command);