javascript - ( Node :8592) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 3): MongoParseError: Invalid connection string

Question

我的代码运行良好，但今天运行时发生了这种情况:

(node:8592) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 3): MongoParseError: Invalid connection string

这是 app.js 的一个片段:

var express               = require("express"),
app                   = express(),
bodyParser            = require("body-parser"),
mongoose              = require("mongoose"),
passport              = require("passport"),
localStrategy         = require("passport-local"),
methodOverride        = require("method-override"),
flash                 = require("connect-flash"),
session               = require("express-session"),
campground            = require("./models/campground"),
comment               = require("./models/comments"),  //name of the model is comment
User                  = require("./models/user"),
seedDB                = require("./seeds");

var campgroundRoutes = require("./routers/campground"),
commentRoutes    = require("./routers/comment"),
authRoutes       = require("./routers/auth");

var url = process.env.DATABASE_URL || "mongodb://localhost:27017/yelp_camp"; 
mongoose.connect(url, { useNewUrlParser: true });
mongoose.set("useFindAndModify", false);
mongoose.set("useCreateIndex", true);

我的代码中缺少什么？

Answer 1

处理返回的 promise 始终是一个好习惯。

var url = process.env.DATABASE_URL || "mongodb://localhost:27017/yelp_camp"; 
mongoose.connect(url, { useNewUrlParser: true })
    .then(() => console.log("Connection Successful"))
    .catch(err => console.log(err));

因此这将避免 UnhandledPromiseRejectionWarning 并且您将知道连接失败的原因。很可能是 URL 的问题。