连接到mongoose会导致ECONNREFUSE

Question

我有一个只包含两行的文件database.coffee  mongoose = require('mongoose') mongoose.connect 'mongodb://localhost:27017/myDatabase'

运行coffee database.coffee时，我得到以下输出：

/SOMEPATH/node_modules/mongodb/lib/server.js:236
    process.nextTick(function() { throw err; })
                                        ^
Error: connect ECONNREFUSED
at errnoException (net.js:901:11)
at Object.afterConnect [as oncomplete] (net.js:892:19)

可能导致此错误的原因是什么？