Setup PostGres with Node.js & Knex
Node.js and PostGres have grown in popularity for several companies to have in their tech stack. Let’s do a quick walkthrough on how to setup and write our first query.
We will be using:
Prerequisites:
- Node and npm already installed
- Postgres database setup (Tutorial Here)
Assuming you have the prerequisites. If you haven’t you can follow the instructions here. Let’s stat by creating a new project. Open Terminal or your CLI tool of choice. I recommend iTerm. Let’s create a new project.
You will then be prompted to name the project, license, etc. You can just click “enter” through these.
Next create our server.js node file and past the following code below.
We are adding the ‘dotenv’ package in order for the our .env file to be read locally. In our .env file we want to add our database connection values. We use the .env file vs having our variables directly in the server.js as it is not committed to our repo and is provides more security.
Create Table & Data
Next let’s run a migration to add some simple data to our PostGres Database. If you don’t have Postgres installed, follow the Steps to install PostGres on Mac tutorial
Now let’s write some simple Knex commands into our server.js file that we added the connection into already. We will add a table and insert a few sample rows of data.
Now let’s run the file by typing node server.js in our terminal, and then verify that the rows did get created.
Query Data
Now let’s put together a couple queries with knex and see the data output.
The final server.js file will look like this:
In Summary
In summary, Node.js, Postgres, and Knex make it very easy to get started. In this simple application, we just ran everything in one file.
This would not be ideal when creating usable and scalable applications.
This post serves as a good proof of concept if you’re wanting to learn how to connect Node.js and Postgres and create queries to bring the data into your application.
I recommend using knex migrations and creating migrations for your tables or for any data you need to populate into the tables. Here is a great cheat sheet for using knex. Cheatsheet. You can find many different Knex commands there to help you continue to learn Knex.
I hope you enjoyed this short 1 file guide on using Node.js, Knex, and PostGres. Checkout our other posts on building more complex applications that will cover application architecture.
