View the source code here
GraphQL is an API query language that aims to replace REST. With GraphQL, you can combine data from multiple sources into one response and expose it as a single API endpoint. We’ll explore one option in this below: querying data from PostgreSQL.
From your terminal, install the necessary packages:
npm i pg-promise graphql graphql-tools cors body-parser express graphql-server-express
First, we’ll setup a PostgreSQL connection instance:
Sample GraphQL Resolver
Now, let’s create a simple GraphQL resolver to retrieve the data from Postgres:
Sample GraphQL Schema
Next, we’ll tell GraphQL which fields we can query and what values to expect in the response:
Sample GraphQL Server
Last, spin up an express server hosting our new API:
And that’s it! You can now point your browser to localhost:3000/graphiql for a GUI representation. Don’t forget to create your users table in Postgres!
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James Mensch is the Director of Engineering at Threatcare and the CEO at Magnifai. I believe in building intelligent products, using data to drive decisions, and engineering for social impact. I write about some of the cool stuff I do with tech, productivity and motivation psychology, and my social innovation projects. Connect with me on LinkedIn or say hi on Twitter.