I am trying to create a simple web application where I can diplay users from a MongoDB database on a React web application.
However I am stuck on a problem with TypeORM and my MongoDB database. Indeed, my backend repository can not access to the database.
Here is my package.json file :
{
"name": "backend",
"version": "1.0.0",
"main": "index.js",
"scripts": {
"build": "tsc",
"dev": "nodemon index.ts",
"start": "node ./dist/index.js",
"typeorm": "ts-node -r tsconfig-paths/register ./node_modules/.bin/typeorm",
"migration:generate": "npm run typeorm -- migration:generate --config src/config/ormconfig.json --connection --name ",
"migration:run": "npm run typeorm -- migration:run"
},
"license": "UNLICENSED",
"dependencies": {
"cors": "^2.8.5",
"dotenv": "^16.0.3",
"express": "^4.18.2",
"mongodb": "^3.6.0",
"typeorm": "^0.3.11"
},
"devDependencies": {
"@types/cors": "^2.8.13",
"@types/express": "^4.17.14",
"@types/mongodb": "^4.0.7",
"@types/node": "^18.11.8",
"nodemon": "^2.0.20",
"ts-node": "^10.9.1",
"typescript": "^4.8.4"
}
}
Here is my connectionService.ts file, which is supposed to create the connection to the database :
import { DataSource, DataSourceOptions } from "typeorm"
import { Utilisateurs } from "../entities/utilisateurs";
class connectionServices{
public myDataSource:DataSource;
constructor(dbConfig: DataSourceOptions){
this.myDataSource = new DataSource(dbConfig)
}
public async getUsers (){
const myusers = this.myDataSource.getMongoRepository(Utilisateurs);
const data = await myusers.find({});
console.log (data);
return data;
}
}
export default (connectionServices);
Here is my index.ts file :
import express from 'express';
import cors from 'cors';
import connectionServices from "./service/connectionService";
function main() {
const app = express();
const service = new connectionServices({
type: "mongodb",
url: "mongodb://localhost:27017",
port: 27017,
database: "users",
synchronize: true,
entities: [
"src/entities/**/*.ts"
],
});
app.use(cors())
app.get('/users/:id', function (req, res, next) {
res.json({msg: 'This is CORS-enabled for all origins!'})
})
app.listen(80, function () {
console.log('CORS-enabled web server listening on port 80')
})
app.get('/', (req, res) => {
res.send('Well done!');
})
app.listen(4321, () => {
console.log('The application is listening on port 4321!');
})
app.get('/users', (req,res) => {
res.send(service.getUsers());
})
}
main();
And finally here is my ormconfig.json file :
{
"type": "mongodb",
"host": "localhost",
"url": "mongodb://localhost:27017",
"port": 27017,
"database": "test",
"synchronize": true,
"logging": false,
"entities": [
"src/entity/**/*.ts"
],
"migrations": [ "src/migration/**/*.ts"
],
"subscribers": [ "src/subscriber/**/*.ts"
],
"cli": {
"entitiesDir": "src/entity", "migrationsDir": "src/migration", "subscribersDir": "src/subscriber"
}
}
The backend builds and launches properly :
However when I type in the url http://localhost:4321/users, I get this error in my terminal and the backend crashes :
I have tried to put the url of the data base, or put the parameter "host": "localhost" with the correct port but nothing worked.
I have looked on several tutorials, videos without success…
If someone sees the solution to my problem that would be great!
2
Answers
In fact the problem was in the index.ts file and in the connectionService.ts file.
In the service, it was missing a function in order to connect to the data base :
And in the index.ts file, I was calling the promise of a table containing the date, and not the data. Here is the working file :
With these modifications, everything works properly.
You didn’t provide your entities. however, I think the problem occurred because typeorm couldn’t find your entities.
try changing
src/entity/**/*.ts
tosrc/entity/**/*{.ts,.js}
.Do the same thing for migration and subscribers if needed.