How to Connect to a PostgreSQL Database Using Node.js
Most real-world applications interact with databases in one way or another. Databases make it easy to persist, analyze and interact with data.
Most programming languages offer support for connecting applications to databases like PostgreSQL. Learn how you can use the node-postgres module to connect a Node application to PostgreSQL.
How to Get Started
To begin by connecting to a local database, you’ll need to have thePostgreSQL server installed.
PostgresSQL is one of the most common relational database systemsdue to its flexibility and power. You might consider using it as an alternative to MySQL if your project is complex or you’re looking for a solution that embraces the open-source ethos.
Create a Node Application
The first step is to create a Node application that you will use to test out the connection code. In your preferred folder, create a new folder.
Navigate to the folder you created and initialize npm.
This command should generate apackage.jsonfile.
Next, create a new file and name itindex.js. You will connect Node to PostgreSQL in this file.
Use node-postgres Module
Thenode-postgresmodule is an npm package that allows you to connect to and interact with a PostgreSQL database. There are two options you can use to connect Node with PostgreSQL using the node-postgres module: a single client or a connection pool. So what should you use?
Use a single client if you only need one static connection at a time. However, if you need to use concurrent and multiple requests, use a connection pool.
Install node-postgres
Run the following command in your terminal to install node-postgres.
If you use node >= 14.x, you will need to install pg@8.2.x o later. You can specify the version number by suffixing it to the installation command like this.
Connecting to PostgreSQL
The node-postgres module requires the following values to connect to a PostgreSQL database.
Create a .env file and add these variables, substituting the corresponding values from your database:
Install the dotenv package to access the .env file.
Inindex.js, import and configure dotenv.
Connect to a PostgreSQL Database Using a Single Client
The code below shows how it’s possible to connect Node to a PostgreSQL server using a single client.
Using a Connection Pool
As already mentioned, a connection pool allows you to make multiple connection requests to your server.
The above examples let you control the database configuration via a .env file. However, it’s possible to also supply these config valuesusing standard environment variables. This approach lets you easily vary the configuration at start-up time.
Consider the following connection code.
In this program, you are not passing the connection object as an argument when initializing Pool. Instead, you must specify the connection details when you invoke the program like this:
Connecting Node to PostgreSQL like this allows you to write a more reusable program.
Doing More With PostgreSQL
To create an application that interacts with databases, you have to connect it to the database first. In this article, you learned how to connect Node to a PostgreSQL database using the node-Postgres module.
Apart from PostgreSQL, there are other database management systems like MySQL you’re able to use in your application. The database tool you choose should be the most compatible with your data needs.
MySQL and PostgreSQL are two of the most popular open-source database management systems, but which one comes out on top?
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