Php codeigniter 3.x中的MongoDB\Driver\Exception\InvalidArgumentException

将CI 2.x中的项目迁移到3.x后，在我使用mongo db的地方显示了以下错误，这在codeigniter版本2中运行良好

消息：无法分析MongoDB URI:“MongoDB://”。无效主机 URI中的字符串

数据库配置

// Generally will be localhost if you're querying from the machine that Mongo is installed on
$config['mongo_host'] = "localhost";
//$config['mongo_host'] = "xxxxxxxxx.compute.amazonaws.com";

// Generally will be 27017 unless you've configured Mongo otherwise
$config['mongo_port'] = 27017;

// The database you want to work from (required)
$config['mongo_db'] = "test_p1";

// Leave blank if Mongo is not running in auth mode
$config['mongo_user'] = "";
$config['mongo_pass'] = "";

// Persistant connections
$config['mongo_persist'] = TRUE;
$config['mongo_persist_key'] = 'ci_mongo_persist';

// Get results as an object instead of an array
$config['mongo_return'] = 'array'; // Set to object

// When you run an insert/update/delete how sure do you want to be that the database has received the query?
// safe = the database has receieved and executed the query
// fysnc = as above + the change has been committed to harddisk <- NOTE: will introduce a performance penalty
$config['mongo_query_safety'] = 'safe';

// Supress connection error password display
$config['mongo_supress_connect_error'] = TRUE;

// If you are having problems connecting try changing this to TRUE
$config['host_db_flag'] = FALSE;

//如果您从安装Mongo的机器上进行查询，则通常为localhost
$config['mongo_host']=“localhost”；
//$config['mongo_host']=“xxxxxxxxx.compute.amazonaws.com”；
//通常为27017，除非您配置了Mongo
$config['mongo_port']=27017；
//要从中工作的数据库（必需）
$config['mongo_db']=“test_p1”；
//如果Mongo未在身份验证模式下运行，则保留为空
$config['mongo_user']=“”；
$config['mongo_pass']=“”；
//持久连接
$config['mongo_persist']=TRUE；
$config['mongo_persist_key']='ci_mongo_persist'；
//将结果作为对象而不是数组获取
$config['mongo_return']='array'；//设为对象
//运行insert/update/delete时，您希望如何确定数据库已收到查询？
//safe=数据库已接收并执行查询
//fysnc=如上所述+更改已提交到硬盘您可能忘记在本地计算机中设置数据库。
i'hv更新了数据库配置@好吧，让我试试，。谢谢