node.js - node express runs and reports an error, as follows

Question

Run supervisor --harmony index and the following error will be reported

Then I shut down and restarted and ran node --harmony index and reported the error as shown below

Answer 1

....Unable to connect to mongo. . . Wasn't it written? .

Answer 2

Unable to connect to the database

Answer 3

mongodb is not enabled or port 27017 is enabled

Answer 4

The reason is that the mongodb service is not started

1. If mongodb is already installed

mongod    #启动命令

2. If mongodb installation is abnormal

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