Creating a GraphQL API with Node.js and PostgreSQL

Have you ever wondered how to build a GraphQL API with Node.js and PostgreSQL? A well-built GraphQL API can turn out to be a great asset for your software application. GraphQL is an excellent tool for managing data and it helps us to interact with our data in various ways by giving us the opportunity to make complex queries.

In this blog post, we will cover the steps needed to create a GraphQL API with Node.js and PostgreSQL. We will go through the process of setting up our database and making our models and mutations. After that, we will test our API using the GraphiQL interface and Firecamp.

Setting Up PostgreSQL

The first step is to set up a PostgreSQL database. PostgreSQL is an open-source relational database management system. It is highly robust and provides a lot of useful features such as data integrity, scalability, and fault tolerance.

We can download and install PostgreSQL from here. After installing PostgreSQL, we can log in to our database with psql -U postgres command and start creating tables and writing queries.

Creating Models

In this step, we will create models that will be used to interact with our PostgreSQL database. To create models with ease, we will use Object-Relational Mapping (ORM) with the help of Sequelize.

Sequelize is a great ORM tool for Node.js that allows us to define models using JavaScript/TypeScript and synchronize these models with our PostgreSQL database.

Writing Mutations

Now that we have our models, we can start writing our GraphQL mutations. Mutations are used in GraphQL to create, update, or delete data in our database. We have to define our mutations in the GraphQL schema using the GraphQL type system.

For writing mutations, we will need to use the graphql-tools package. This package helps us to define our schema using the GraphQL Schema Definition language.

We can install graphql-tools using the following command:

npm install graphql-tools

Testing with GraphiQL

After writing our schema and mutations, we can now test our API. To test our API we will use the GraphiQL interface. GraphiQL is an in-browser tool for writing, validating, and testing queries and mutations in GraphQL.

We can start the GraphiQL server using the following command:

npm run start-server

Once the server is running, we can go to http://localhost:3000/graphiql to start testing our API.

Testing with Firecamp

Firecamp is an open-source GraphQL client that allows us to test GraphQL APIs. It gives us the ability to query multiple APIs at the same time and visualize the response in an interactive way.

We can use Firecamp to start testing our API. Once on Firecamp, we need to add the URL of our GraphiQL endpoint in the Firecamp URL field. We can then write queries and mutations in Firecamp and test them against our API.

Conclusion

In this blog post, we have seen how to create a GraphQL API with Node.js and PostgreSQL. We started off by setting up our database and creating our models with the help of Sequelize. After that, we wrote our GraphQL mutations and tested our API using the GraphiQL interface and Firecamp.

Creating a GraphQL API with Node.js and PostgreSQL is not a difficult task. With the help of tools such as Sequelize and Firecamp we can create APIs with ease.