Uncaught exception 'MongoConnectionException' with message 'Unknown error' in...

$mongo = new Mongo();

执行时，报错："Uncaught exception 'MongoConnectionException' with message 'Unknown error' in..."

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have you actually got the server running? Only it looks like your error relates to a failure to connect and you've made no mention of the server or where it is located (localhost on the default port for example)

原因：连接错误，检查服务端是否运行？连接url是否正确？
new Mongo()（默认连接本机的27017端口）

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建一个DB文件夹来存放数据库文件路径 路径d:\DB\data


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保持此窗口为开启状态，重新执行php代码程序，就可以正确执行了