BUILDING A SIMPLE REST API FOR INVENTORY MANAGEMENT

 INTRODUCTION :

Representational State Transfer (REST) is an architectural style that defines a set of constraints to be used for creating web services. REST API is a way of accessing web services in a simple and flexible way without having any processing.

There are numerous types of APIs, making it difficult for new developers to differentiate between each kind. In particular, Representational State Transfer (REST) is a software architectural style that developers apply to web APIs. REST APIs provide simple, uniform interfaces because they can be used to make data, content, algorithms, media, and other digital resources available through web URLs.

The method is the type of request you send to the server. The four main resource methods that are associated with REST APIs are:

1. GET: This method allows for the server to find the data you requested and sends it back to you.
2. PUT: If you perform the ‘PUT’ request, then the server will update an entry in the database.
3. POST: This method permits the server to create a new entry in the database.
4. DELETE: This method allows the server to delete an entry in the database.      

NOW PERFORM FOLLOWING STEPS :

STEP 1 : SETUP YOUR PHP ENVIRONMENT 

Before you begin building your REST API, ensure you have a working PHP environment. You can use tools like XAMPP, WAMP, or a web hosting service.

You can use the below reference link to Set Up your PHP Environment.

https://chiragvalvai.blogspot.com/2023/12/steps-to-install-process-of-php-with.html

STEP 2 : WRITE PHP CODE FOR API 

<?php

include 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'GET' && isset($_GET['items'])) {

    <?php

include 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'GET') {

    $sql = "SELECT * FROM items";

    $result = $conn->query($sql);

    if ($result->num_rows > 0) {

        $items = array();

        while ($row = $result->fetch_assoc()) {

            $items[] = $row;

        }

        echo json_encode($items);

    } else {

        echo "No items found.";

    }

}

?>

}

if ($_SERVER['REQUEST_METHOD'] === 'GET' && isset($_GET['items']) && isset($_GET['id'])) {

    $id = $_GET['id'];

    <?php

include 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'GET' && isset($_GET['items']) && isset($_GET['id'])) {

    $item_id = $_GET['id'];

    $sql = "SELECT * FROM items WHERE id = $item_id";

    $result = $conn->query($sql);

    if ($result->num_rows > 0) {

        // Fetch the item data

        $item = $result->fetch_assoc();

        header('Content-Type: application/json');

        echo json_encode($item);

    } else {

        header("HTTP/1.0 404 Not Found");

        echo "Item not found.";

    }

}

?>

}

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['items'])) {

    <?php

include 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'POST') {

    $name = $_POST['name'];

    $description = $_POST['description'];

    $price = $_POST['price'];

    $quantity = $_POST['quantity'];

    $category = $_POST['category'];

    $sql = "INSERT INTO items (name, description, price, quantity, category) VALUES ('$name', '$description', $price, '$quantity', '$category')";

    if ($conn->query($sql) === TRUE) {

        echo "Item added successfully.";

    } else {

        echo "Error: " . $conn->error;

    }

}

?>

}

if ($_SERVER['REQUEST_METHOD'] === 'PUT' && isset($_PUT['items']) && isset($_PUT['id'])) {

    $id = $_PUT['id'];

<?php

include 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'PUT') {

    parse_str(file_get_contents("php://input"), $_PUT);

    $id = $_PUT['id'];

    $name = $_PUT['name'];

    $description = $_PUT['description'];

    $price = $_PUT['price'];

    $quantity = $_PUT['quantity'];

    $category = $_PUT['category'];

    $sql = "UPDATE items SET name='$name', description='$description', price=$price, quantity='$quantity', category='$category' WHERE id=$id";

    if ($conn->query($sql) === TRUE) {

        echo "Item updated successfully.";

    } else {

        echo "Error: " . $conn->error;

    }

}

?>

}

if ($_SERVER['REQUEST_METHOD'] === 'DELETE' && isset($_DELETE['items']) && isset($_DELETE['id'])) {

    $id = $_DELETE['id'];

<?php

include 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'DELETE') {

    parse_str(file_get_contents("php://input"), $_DELETE);

    $id = $_DELETE['id'];

    $sql = "DELETE FROM items WHERE id=$id";

    if ($conn->query($sql) === TRUE) {

        echo "Item deleted successfully.";

    } else {

        echo "Error: " . $conn->error;

    }

}

?>

STEP 4 : TEST YOUR API 

Once you've written the code for your API, you can test it using tools like Postman or curl. Make requests to the endpoints you've defined, and ensure that the API behaves as expected.

CONCLUSION :

Creating a REST API for inventory management is a valuable skill in today's tech-savvy world. It allows businesses to automate and streamline their operations while providing a modern and efficient user experience. With PHP and a well-designed database, you can create a powerful inventory management system that suits your specific needs.

Remember that this tutorial provides a basic structure for your REST API, and you may need to tailor it to your project's requirements. Additionally, it's important to secure your API by implementing authentication and authorization mechanisms for production use.

Building a RESTful API can be a rewarding endeavor, and it opens up a world of possibilities for connecting your inventory system to various applications and platforms. Good luck with your API development journey!