Connecting Nest.js application with TypeORM and Postgres

In this lesson, the application will be connected to a database, utilizing TypeORM as the bridge between object-oriented code and SQL queries in a Nest.js context. As a best practice, isolating database connection configurations into environment variables ensures both security and easier environment management. Learning how to connect Nest.js applications to a Postgres database provides a comprehensive understanding of backend architecture, an area where Nest.js offers more out of the-box features compared to Express.

"@nestjs/typeorm": "^9.0.1",
"pg": "^8.10.0",
"typeorm": "^0.3.15"

Should TypeScript typings for TypeORM be absent, installation as a devDependency is possible.

"devDependencies": {
  "@types/node": "^18.11.18"
}

---
title: Connecting Nest.js application with TypeORM and Postgres
privateVideoUrl: https://fullstack.wistia.com/medias/rq2stfd172
isPublicLesson: true
---

## Connecting Nest.js application with TypeORM and Postgres

In this lesson, the application will be connected to a database, utilizing TypeORM as the bridge between object-oriented code and SQL queries in a Nest.js context. As a best practice, isolating database connection configurations into environment variables ensures both security and easier environment management. Learning how to connect Nest.js applications to a Postgres database provides a comprehensive understanding of backend architecture, an area where Nest.js offers more out of the-box features compared to Express.

### Install Dependencies

```bash
"@nestjs/typeorm": "^9.0.1",
"pg": "^8.10.0",
"typeorm": "^0.3.15"
```

Should TypeScript typings for TypeORM be absent, installation as a devDependency is possible.

```bash
"devDependencies": {
  "@types/node": "^18.11.18"
}
```

First, installation of the required dependencies in the application is necessary. These packages can be copied into the `package.json` file, followed by running the command `npm install`.

### Import TypeORM Module to App Module

AppModule is our root module, we have to configure the TypeORM module here.

```ts
imports: [
  TypeOrmModule.forRoot({
    type: 'postgres',
    host: 'localhost',
    port: 5432,
    username: 'your_username',
    password: 'your_db_password',
    database: 'n-test',
    entities: [],
    synchronize: true,
}),
```

Haider Malik

In this video, I'm going to teach you how to connect NestJS application with

NestJS provides multiple drivers to connect with database.

If you want to use MongoDB, you can also do that.

If you want to use MySQL, if you want to use Postgres, you can do that.

In this video, I'm going to implement the Postgres with NestJS.

The type orem is an object relational mapper.

You will write the code in JavaScript objects and these objects or classes will

If you want to write SQL queries, you don't need to write plain SQL query, you

First of all, you have to install a couple of dependencies.

We need NestJS type orem package and Postgres driver and type orem.

Open the package.json file and you have to install these dependencies.

Let me install all of these dependencies.

I'm going to install as a dev dependency.

We already have this package types add node.

We install these packages, NestJS type orem, Postgres and type orem.

So now we need to import the type orem module into our root module.

The our case root module is our app module.

So we have to call this method from type orem module and you have to provide

strings or connection properties like type, post, port, username, password,

Whenever you will create a new entity, you have to register it here.

For synchronize means whenever I will run the application, please delete the

Synchronize please delete everything from the table but do not use synchronize

otherwise you will lose the production data.

Whenever you have to create a new entity, you have to add it here inside the

So the for root method sports all the configuration properties exposed by the

If you don't have, you can install the Postgres admin.

We have to create a new database right now.

I'm going to create a new database, spotify clone.

Go to the app module and we have to import the type or a module here.

It's not giving me this suggestion from Nest JSType or M and we need to get

Post which should be localhost and when you specify the port for Postgres, I

You have to provide your password for me.

I specified the database name and we have empty entities right now.

I don't have any entity and SiliconIs are to true.

How can you verify we have successfully connected to type or M?

You can use data source object in the app module.

Let's add the type of the driver which is Postgres.

Now we have made the connection successfully.

You can see DB name which is Spotify clone.

You can also check the songs table inside the Spotify.

I don't have any song because we did not create any entity right now.

But we have successfully connected to the Postgres database.

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