Learn how to integrate PostgreSQL with a REST API using no-code tools, JavaScript CRUD operations, auto-generated APIs, and REST servers. Bobcares’ API Integrations Service supports planning, setup, and ongoing management.
A PostgreSQL REST API is a web service that allows applications to interact with a PostgreSQL database using HTTP requests. Instead of relying on SQL queries directly, it uses standard HTTP methods such as GET, POST, PUT, and DELETE.
The term is often used interchangeably with PostgreSQL APIs. The key distinction is that PostgreSQL REST APIs rely on a web-based interface, REST principles, and HTTP methods.
REST API stands for Representational State Transfer API. It enables communication between systems over the internet through a request-and-response model, most commonly using JSON.
Clients send requests to a server through a web URL using an HTTP method. The server responds with the requested resource, which may be HTML, XML, an image, or JSON. JSON is the most widely used format for modern services.
HTTP methods align directly with CRUD operations for managing resources. When working with REST APIs and databases, it’s also helpful to understand key API security best practices that protect your endpoints and data against unauthorized access.
An Overview
Different Methods for PostgreSQL REST API Connection
Method 1. Using Hevo Data for PostgreSQL REST API Connection
Hevo Data is a no-code data pipeline for transferring data from REST APIs to PostgreSQL. The process involves two steps.
Step 1. Configure the Source
Connect Hevo Data to a REST API source by assigning a pipeline name and selecting the request method (GET or POST).
Provide the API endpoint URL, data root, authentication details such as username and password, and details for query parameters and API headers.
Step 2. Configure the Destination
Select PostgreSQL as the destination and enter the required credentials to complete the REST API to PostgreSQL setup.
Method 2. Using JavaScript for CRUD Operations
This approach creates a REST API for PostgreSQL using JavaScript by defining routes that handle CRUD operations.
Step 1. Create and Export Functions
Six functions are created, one for each route:
- GET / | displayHome()
- GET users | getUsers()
- GET /users/:id | getUserById()
- POST users | createUser()
- PUT /users/:id | updateUser()
- DELETE /users/:id | deleteUser()
The root endpoint is defined in index.js. The remaining endpoints are implemented in queries.js to handle user data operations.
Step 2. Get All Users
This endpoint retrieves all users from the database and orders them by ID.
const getUsers = (request, response) => {
pool.query('SELECT * FROM users ORDER BY id ASC', (error, results) => {
if (error) {
throw error
}
response.status(200).json(results.rows)
})
}
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Step 3. Get a Single User by ID
The user ID is extracted from the URL and used in a WHERE clause.
const getUserById = (request, response) => {
const id = parseInt(request.params.id)
pool.query('SELECT * FROM users WHERE id = $1', [id], (error, results) => {
if (error) {
throw error
}
response.status(200).json(results.rows)
})
}Step 4. Create a New User
The POST request extracts values from the request body and inserts them into the database.
const createUser = (request, response) => {
const { name, email } = request.body
pool.query(
‘INSERT INTO users (name, email) VALUES ($1, $2)’,
[name, email],
(error, results) => {
if (error) {
throw error
}
response.status(201).send(`User added with ID: ${result.insertId}`)
}
)
}
Step 5. Update an Existing User
The PUT method modifies existing records using an UPDATE query. PUT requests are idempotent, producing the same result when repeated.
const updateUser = (request, response) => {
const id = parseInt(request.params.id)
const { name, email } = request.body
pool.query(
'UPDATE users SET name = $1, email = $2 WHERE id = $3',
[name, email, id],
(error, results) => {
if (error) {
throw error
}
response.status(200).send(`User modified with ID: ${id}`)
}
)
}Step 6. Delete a User
This endpoint removes a user based on the ID provided in the URL.
const deleteUser = (request, response) => {
const id = parseInt(request.params.id)
pool.query('DELETE FROM users WHERE id = $1', [id], (error, results) => {
if (error) {
throw error
}
response.status(200).send(`User deleted with ID: ${id}`)
})
}
Step 7. Export CRUD Functions
All functions are exported, so they are available in index.js.
module.exports = {
getUsers,
getUserById,
createUser,
updateUser,
deleteUser,
}Step 8. Configure Routes in index.js
The exported functions are imported and mapped to their respective routes.
const db = require('./queries')
app.get('/users', db.getUsers)
app.get('/users/:id', db.getUserById)
app.post('/users', db.createUser)
app.put('/users/:id', db.updateUser)
app.delete('/users/:id', db.deleteUser)
The complete index.js file serves as the API entry point.
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Method 3: Using RAPID RESTful API for PostgreSQL
Step 1. System Requirements
- Linux or Windows
- Node.js
- OpenSSL installed
- Tested with PostgreSQL 9.3 and later
Linux systems must allow Node.js to bind to lower ports without root access.
Step 2. Installation
npm install psql-api –save
Step 3. Create a Server File
server = require("psql-api");
server.start();
Step 4. Install as a Standalone Server
git clone https://github.com/QBisConsult/psql-api.git
Step 5. Install Dependencies
sudo npm install
Step 6. Start the Server
node start.js
The server opens two ports, one for administration over HTTPS and another for PostgreSQL REST API requests. Access is available through a web interface using a self-signed SSL certificate generated on first startup.
This PostgreSQL REST API supports CRUD operations, automatically imports the database structure, and returns JSON. Batch commands are supported and transactions are enabled by default. Database structure management requires third-party tools such as pgAdmin.
Method 4: Automatic APIs Using PostgREST
Step 1. Create an API Schema
CREATE SCHEMA api;Step 2. Create a Table
CREATE TABLE api.books (
index SERIAL,
title TEXT,
author VARCHAR(255),
genre TEXT
);
The SERIAL index generates an auto-incremented ID.
Step 3. Configure Security
A PostgreSQL role is created to limit database access through the API.
CREATE ROLE apiOperator nologin;
GRANT usage ON SCHEMA api TO apiOperator;
GRANT all ON api.books TO apiOperator;
GRANT usage, SELECT ON SEQUENCE api.books_index_seq TO operator;
Step 4. Configure PostgREST
Configuration is handled using the postgrest.conf file.
db-uri = "localhost"
db-schema = "api"
db-anon-role = "apiOperator"
Step 5. Make API Requests
Retrieve all rows:
curl "http://localhost:3000/books"
Limit results:
curl "http://localhost:3000/books?limit=5"
Select specific columns:
curl "http://localhost:3000/books?limit=5&select=title,author"Create a new record:
curl "http://localhost:3000/books" \
-X POST -H "Content-Type: application/json" \
-d '{
"author": "Ernest Hemingway",
"title": "The Sun Also Rises"
}'
Delete a record:
curl -X DELETE "http://localhost:3000/books?title=like."The Sun*"
PostgREST supports full CRUD functionality and exposes PostgreSQL data directly through HTTP requests.
Conclusion
Integrating PostgreSQL with a REST API can be approached in several ways, depending on application requirements, development effort, and operational complexity. No-code tools, auto-generated APIs, and custom JavaScript implementations all support CRUD operations and JSON-based data exchange while enabling controlled access to PostgreSQL.
At Bobcares, this type of PostgreSQL and REST API integration work is routinely handled for clients across different use cases, including setup, troubleshooting, and long-term support to keep API-driven database access stable and reliable.
