mongoose 数据库连接

var mongoose = require('mongoose');
mongoose.connect('mongodb://127.0.0.1:27017/whhhh', { useMongoClient: true });
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function (callback) {
    console.log("数据库成功连接");
});