Why am I getting "mongoose.connect is not a function" when trying to connect with mongoose?

Question

I am new to Node.js and am trying to build a node/express/mongoose server app with TypeScript.

Here is my app.ts file:

// lib/app.ts
import express from 'express';
import * as bodyParser from 'body-parser';
import { Routes } from './routes/crmRoutes';
import * as mongoose from "mongoose";

class App {
  public app: express.Application;
  public routePrv: Routes = new Routes();
  public mongoUrl: string = 'mongodb://localhost/TodosDB';

  constructor() {
    this.app = express();
    this.config();
    this.routePrv.routes(this.app);
    this.mongoSetup();
  }

  private mongoSetup(): void {
    mongoose.connect(this.mongoUrl, {
      useNewUrlParser: true,
      useUnifiedTopology: true
    });
  }

  private config(): void {
    // support application/json type post data
    this.app.use(bodyParser.json());
    //support application/x-www-form-urlencoded post data
    this.app.use(bodyParser.urlencoded({ extended: false }));
  }
}

export default new App().app;

However, when I try to compile my application, I get:

TypeError: mongoose.connect is not a function

I've used up all my Google skill -- no luck.

Can anyone tell me what I'm doing wrong?

place the following in mongoSetup function and let me know what you'r getting ` mongoose.connect(this.mongoUrl, { useNewUrlParser: true, useUnifiedTopology: true }).then(function(data) { console.log("data = ", data); }).catch(function(err) { console.log(err); });` — Alok Deshwal, Sep 15 '19 at 16:05
I just copied your code and replace first line with `import * as express from 'express';` and it simple worked. — Alok Deshwal, Sep 15 '19 at 16:10
@AlokDeshwal -- thanks for your interest. I can't log to the console because the code won't compile. Also, I replaced my import statement with what you had, and I get the same result. Didn't change anything. — Nick Hodges, Sep 15 '19 at 19:32
I made your change, did a `tsc ./lib/server.js` and that compiled. Then it ran. Thanks for the help. — Nick Hodges, Sep 15 '19 at 19:42
By the way I really like the way you have designed your app class. :-) — Khuram, Nov 14 '21 at 15:38
I would like to know about the skeleton and file (MVC or other) organization of your project. Can you please share that? Thanks! :-) — Khuram, Nov 14 '21 at 17:58

score 31 · Answer 1 · answered Aug 09 '20 at 08:39

31

Replace:

import * as mongoose from "mongoose";

With:

import mongoose from "mongoose";

answered Aug 09 '20 at 08:39

Vijay Shaaruck

611
8
5

2

https://stackoverflow.com/a/56348146/5308115 - explanation – yashodha_h Jun 24 '21 at 17:04

score 18 · Answer 2 · answered Dec 26 '19 at 21:52

18

This worked for me: replace

import * as mongoose from "mongoose";

with

import mongoose = require("mongoose");

answered Dec 26 '19 at 21:52

sffc

6,186
3
44
68

score 7 · Answer 3 · answered Apr 24 '20 at 17:38

7

if you have "esModuleInterop": true, in your tsconfig.json it forces you to import mongoose differently so change the above option or change the way you import mongoose

answered Apr 24 '20 at 17:38

javad bat

4,236
6
26
44

score 3 · Answer 4 · answered Mar 06 '21 at 02:58

A nice way is to import only the methods you need eg.

import { connect } from 'mongoose';

Then in your class

class App {
  private async mongoSetup(): Promise<void> {
    await connect(this.mongoUrl, {
        useNewUrlParser: true,
        useUnifiedTopology: true
    });
  }
}

Why am I getting "mongoose.connect is not a function" when trying to connect with mongoose?

4 Answers4

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