How To Create A Simple REST API in PHP? Step By Step Guide!

Last update: February 17, 2017
Date posted: February 17, 2017
Created by ninjazhai
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Previously, we learned the basics of JavaScript from our JavaScript tutorial for beginners.

Today, we will explore the creation of a simple REST API using the PHP programming language. We will delve into the implementation of CRUD (Create, Read, Update, Delete) functionality and examine the implementation of search and pagination functionality within the context of a REST API.

This knowledge will be crucial as we utilize this API for data retrieval within our JavaScript project. Join us as we embark on this step-by-step guide to building a robust and efficient REST API.

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Project Overview

What is REST API?

To define “REST API”, we have to know what is “REST” is and what “API” first. I’ll do my best to explain it in simple terms because REST has a lot of concepts inside of it that could mean a lot of things.

REST stands for “REpresentational State Transfer”. It is a concept or architecture for managing information over the internet. REST concepts are referred to as resources. A representation of a resource must be stateless. It is usually represented by JSON. This post is worth reading: How I Explained REST to My Wife?

API stands for “Application Programming Interface.” It is a set of rules that allows one software application to talk to another. Those “rules” can include the create, read, update and delete operations.

REST API enables your application to cooperate with one or several different applications using REST concepts. If you want to learn more, watch the video below.

Why do we need REST API?

REST API is needed in many applications because this is the lightest way to create, read, update or delete information between different applications over the internet or HTTP protocol. This information is presented to the user instantly, primarily if you use JavaScript to render the data on a webpage.

Where is REST API used?

REST API can be used by any application connecting to the internet. If data from an application can be created, read, updated, or deleted using another, it usually means a REST API is used.

REST API in our tutorials

A REST API is needed for our JavaScript CRUD tutorial. But don’t mind it for now. We will do it one step at a time. You don’t need to learn all of it as well. Just choose what you need to learn.

But one thing is for sure, this source code is good enough and works for our JavaScript tutorials.

Let’s start coding!

Setup the database

Using PhpMyAdmin, create a new api_db database. Yes, api_db is the database name. After that, run the following SQL queries to create new tables with sample data.

Create categories table

CREATE TABLE IF NOT EXISTS `categories` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(256) NOT NULL,
  `description` text NOT NULL,
  `created` datetime NOT NULL,
  `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=19 ;

Dump data for categories table

INSERT INTO `categories` (`id`, `name`, `description`, `created`, `modified`) VALUES
(1, 'Fashion', 'Category for anything related to fashion.', '2014-06-01 00:35:07', '2014-05-30 17:34:33'),
(2, 'Electronics', 'Gadgets, drones and more.', '2014-06-01 00:35:07', '2014-05-30 17:34:33'),
(3, 'Motors', 'Motor sports and more', '2014-06-01 00:35:07', '2014-05-30 17:34:54'),
(5, 'Movies', 'Movie products.', '0000-00-00 00:00:00', '2016-01-08 13:27:26'),
(6, 'Books', 'Kindle books, audio books and more.', '0000-00-00 00:00:00', '2016-01-08 13:27:47'),
(13, 'Sports', 'Drop into new winter gear.', '2016-01-09 02:24:24', '2016-01-09 01:24:24');

Products table

CREATE TABLE IF NOT EXISTS `products` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) NOT NULL,
  `description` text NOT NULL,
  `price` decimal(10,0) NOT NULL,
  `category_id` int(11) NOT NULL,
  `created` datetime NOT NULL,
  `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=65 ;

Dump data for products table

INSERT INTO `products` (`id`, `name`, `description`, `price`, `category_id`, `created`, `modified`) VALUES
(1, 'LG P880 4X HD', 'My first awesome phone!', '336', 3, '2014-06-01 01:12:26', '2014-05-31 17:12:26'),
(2, 'Google Nexus 4', 'The most awesome phone of 2013!', '299', 2, '2014-06-01 01:12:26', '2014-05-31 17:12:26'),
(3, 'Samsung Galaxy S4', 'How about no?', '600', 3, '2014-06-01 01:12:26', '2014-05-31 17:12:26'),
(6, 'Bench Shirt', 'The best shirt!', '29', 1, '2014-06-01 01:12:26', '2014-05-31 02:12:21'),
(7, 'Lenovo Laptop', 'My business partner.', '399', 2, '2014-06-01 01:13:45', '2014-05-31 02:13:39'),
(8, 'Samsung Galaxy Tab 10.1', 'Good tablet.', '259', 2, '2014-06-01 01:14:13', '2014-05-31 02:14:08'),
(9, 'Spalding Watch', 'My sports watch.', '199', 1, '2014-06-01 01:18:36', '2014-05-31 02:18:31'),
(10, 'Sony Smart Watch', 'The coolest smart watch!', '300', 2, '2014-06-06 17:10:01', '2014-06-05 18:09:51'),
(11, 'Huawei Y300', 'For testing purposes.', '100', 2, '2014-06-06 17:11:04', '2014-06-05 18:10:54'),
(12, 'Abercrombie Lake Arnold Shirt', 'Perfect as gift!', '60', 1, '2014-06-06 17:12:21', '2014-06-05 18:12:11'),
(13, 'Abercrombie Allen Brook Shirt', 'Cool red shirt!', '70', 1, '2014-06-06 17:12:59', '2014-06-05 18:12:49'),
(26, 'Another product', 'Awesome product!', '555', 2, '2014-11-22 19:07:34', '2014-11-21 20:07:34'),
(28, 'Wallet', 'You can absolutely use this one!', '799', 6, '2014-12-04 21:12:03', '2014-12-03 22:12:03'),
(31, 'Amanda Waller Shirt', 'New awesome shirt!', '333', 1, '2014-12-13 00:52:54', '2014-12-12 01:52:54'),
(42, 'Nike Shoes for Men', 'Nike Shoes', '12999', 3, '2015-12-12 06:47:08', '2015-12-12 05:47:08'),
(48, 'Bristol Shoes', 'Awesome shoes.', '999', 5, '2016-01-08 06:36:37', '2016-01-08 05:36:37'),
(60, 'Rolex Watch', 'Luxury watch.', '25000', 1, '2016-01-11 15:46:02', '2016-01-11 14:46:02');

Connect to database

The code below shows the database credentials and a method to get a database connection using PDO. If you’re not yet familiar with PDO, please learn from our PHP OOP CRUD Tutorial first.

  • Create api folder. Open api folder.
  • Create config folder. Open config folder.
  • Create a database.php file. Place the following code inside it.
<?php
class Database{

    // specify your own database credentials
    private $host = "localhost";
    private $db_name = "api_db";
    private $username = "root";
    private $password = "";
    public $conn;

    // get the database connection
    public function getConnection(){

        $this->conn = null;

        try{
            $this->conn = new PDO("mysql:host=" . $this->host . ";dbname=" . $this->db_name, $this->username, $this->password);
            $this->conn->exec("set names utf8");
        }catch(PDOException $exception){
            echo "Connection error: " . $exception->getMessage();
        }

        return $this->conn;
    }
}
?>

Read products

Product object

The code below shows a class named Product with several of its properties. It also shows a constructor method that will accept the database connection.

We will use this class to read data from the database.

  • Open api folder.
  • Create objects folder.
  • Open objects folder.
  • Create product.php file.
  • Place the following code inside it.
<?php
class Product{

    // database connection and table name
    private $conn;
    private $table_name = "products";

    // object properties
    public $id;
    public $name;
    public $description;
    public $price;
    public $category_id;
    public $category_name;
    public $created;

    // constructor with $db as database connection
    public function __construct($db){
        $this->conn = $db;
    }
}
?>

Create file to read products

The code below shows headers about who can read this file and which type of content it will return.

In this case, our read.php the file can be read by anyone (asterisk * means all) and will return a data in JSON format.

  • Open api folder.
  • Create product folder.
  • Open product folder.
  • Create read.php file.
  • Place the following code inside it.
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");

// database connection will be here

Connect to database and products table

In the code below, we included the database.php and product.php files. These are the files we created earlier.

We need to use the getConnection() method of the Database class to get a database connection. We pass this connection to the Product class.

Replace of // database connection will be here comment of read.php file with the following code.

// include database and object files
include_once '../config/database.php';
include_once '../objects/product.php';

// instantiate database and product object
$database = new Database();
$db = $database->getConnection();

// initialize object
$product = new Product($db);

// read products will be here

Read products from the database

In the code below, we used the read() method of Product class to read data from the database. Through the $num variable, we check if there are records found.

If there are records found, we loop through it using the while loop, add each record to the $products_arr array, set a 200 OK response code and show it to the user in JSON format.

Replace of // read products will be here comment of read.php file with the following code.

// query products
$stmt = $product->read();
$num = $stmt->rowCount();

// check if more than 0 record found
if($num>0){

    // products array
    $products_arr=array();
    $products_arr["records"]=array();

    // retrieve our table contents
    // fetch() is faster than fetchAll()
    // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        // extract row
        // this will make $row['name'] to
        // just $name only
        extract($row);

        $product_item=array(
            "id" => $id,
            "name" => $name,
            "description" => html_entity_decode($description),
            "price" => $price,
            "category_id" => $category_id,
            "category_name" => $category_name
        );

        array_push($products_arr["records"], $product_item);
    }

    // set response code - 200 OK
    http_response_code(200);

    // show products data in json format
    echo json_encode($products_arr);
}

// no products found will be here

Add product “read()” method

We used the read() method in the previous section but it does not exist yet in the Product class. We need to add this read() method. The code below shows the query to get records from the database.

  • Open objects folder.
  • Open product.php file.
  • Place the following code inside the Product class.
  • To make sure you added it correctly, place the code before the last closing curly brace.
// read products
function read(){

    // select all query
    $query = "SELECT
                c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created
            FROM
                " . $this->table_name . " p
                LEFT JOIN
                    categories c
                        ON p.category_id = c.id
            ORDER BY
                p.created DESC";

    // prepare query statement
    $stmt = $this->conn->prepare($query);

    // execute query
    $stmt->execute();

    return $stmt;
}

Tell the user no products found

If the $num variable has a value of zero or negative, it means there are no records returned from the database. We need to tell the user about this.

On the code below, we set the response code to 404 - Not found and a message that says No products found.

Replace of // no products found will be here comment of read.php file with the following code.

else{

    // set response code - 404 Not found
    http_response_code(404);

    // tell the user no products found
    echo json_encode(
        array("message" => "No products found.")
    );
}

Output

You need to use POSTMAN to test our API. Download your version of POSTMAN here.

Launch POSTMAN. Enter the following as the request URL.

http://localhost/api/product/read.php

Click the blue “Send” button.

  • Output if there are product data.
  • Output if there are no product data.

Create Product

Create create.php file

  • Open product folder.
  • Create a new create.php file.
  • Open that file and put the following code inside it.
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: POST");
header("Access-Control-Max-Age: 3600");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

// get database connection
include_once '../config/database.php';

// instantiate product object
include_once '../objects/product.php';

$database = new Database();
$db = $database->getConnection();

$product = new Product($db);

// get posted data
$data = json_decode(file_get_contents("php://input"));

// make sure data is not empty
if(
    !empty($data->name) &&
    !empty($data->price) &&
    !empty($data->description) &&
    !empty($data->category_id)
){

    // set product property values
    $product->name = $data->name;
    $product->price = $data->price;
    $product->description = $data->description;
    $product->category_id = $data->category_id;
    $product->created = date('Y-m-d H:i:s');

    // create the product
    if($product->create()){

        // set response code - 201 created
        http_response_code(201);

        // tell the user
        echo json_encode(array("message" => "Product was created."));
    }

    // if unable to create the product, tell the user
    else{

        // set response code - 503 service unavailable
        http_response_code(503);

        // tell the user
        echo json_encode(array("message" => "Unable to create product."));
    }
}

// tell the user data is incomplete
else{

    // set response code - 400 bad request
    http_response_code(400);

    // tell the user
    echo json_encode(array("message" => "Unable to create product. Data is incomplete."));
}
?>

Product create() method

  • Open objects folder.
  • Open product.php file.
  • The previous section will not work without the following code inside the Product (objects/product.php) class.
// create product
function create(){

    // query to insert record
    $query = "INSERT INTO
                " . $this->table_name . "
            SET
                name=:name, price=:price, description=:description, category_id=:category_id, created=:created";

    // prepare query
    $stmt = $this->conn->prepare($query);

    // sanitize
    $this->name=htmlspecialchars(strip_tags($this->name));
    $this->price=htmlspecialchars(strip_tags($this->price));
    $this->description=htmlspecialchars(strip_tags($this->description));
    $this->category_id=htmlspecialchars(strip_tags($this->category_id));
    $this->created=htmlspecialchars(strip_tags($this->created));

    // bind values
    $stmt->bindParam(":name", $this->name);
    $stmt->bindParam(":price", $this->price);
    $stmt->bindParam(":description", $this->description);
    $stmt->bindParam(":category_id", $this->category_id);
    $stmt->bindParam(":created", $this->created);

    // execute query
    if($stmt->execute()){
        return true;
    }

    return false;

}

Output

To test for the successful creation of a product, open POSTMAN. Enter the following as the request URL

http://localhost/api/product/create.php
  • Click the “Body” tab.
  • Click “raw”.
  • Enter this JSON value:
{
    "name" : "Amazing Pillow 2.0",
    "price" : "199",
    "description" : "The best pillow for amazing programmers.",
    "category_id" : 2,
    "created" : "2018-06-01 00:35:07"
}
  • It should look like this:
  • If the system is unable to create the product, it should look like this:
  • If the sent data is incomplete, for example, it is missing the price data, the output should look like this:

Read One Product

Create read_one.php file

  • Open product folder.
  • Create a w read_one.php file.
  • Open that file and put the following code.
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Headers: access");
header("Access-Control-Allow-Methods: GET");
header("Access-Control-Allow-Credentials: true");
header('Content-Type: application/json');

// include database and object files
include_once '../config/database.php';
include_once '../objects/product.php';

// get database connection
$database = new Database();
$db = $database->getConnection();

// prepare product object
$product = new Product($db);

// set ID property of record to read
$product->id = isset($_GET['id']) ? $_GET['id'] : die();

// read the details of product to be edited
$product->readOne();

if($product->name!=null){
    // create array
    $product_arr = array(
        "id" =>  $product->id,
        "name" => $product->name,
        "description" => $product->description,
        "price" => $product->price,
        "category_id" => $product->category_id,
        "category_name" => $product->category_name

    );

    // set response code - 200 OK
    http_response_code(200);

    // make it json format
    echo json_encode($product_arr);
}

else{
    // set response code - 404 Not found
    http_response_code(404);

    // tell the user product does not exist
    echo json_encode(array("message" => "Product does not exist."));
}
?>

Product readOne() method

  • Open objects folder.
  • Open product.php file.
  • The previous section will not work without the following code inside the Product class.
// used when filling up the update product form
function readOne(){

    // query to read single record
    $query = "SELECT
                c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created
            FROM
                " . $this->table_name . " p
                LEFT JOIN
                    categories c
                        ON p.category_id = c.id
            WHERE
                p.id = ?
            LIMIT
                0,1";

    // prepare query statement
    $stmt = $this->conn->prepare( $query );

    // bind id of product to be updated
    $stmt->bindParam(1, $this->id);

    // execute query
    $stmt->execute();

    // get retrieved row
    $row = $stmt->fetch(PDO::FETCH_ASSOC);

    // set values to object properties
    $this->name = $row['name'];
    $this->price = $row['price'];
    $this->description = $row['description'];
    $this->category_id = $row['category_id'];
    $this->category_name = $row['category_name'];
}

Output

  • First, we will test for a product that exists. Open POSTMAN. Enter the following as the request URL. Click the blue “Send” button.
http://localhost/api/product/read_one.php?id=60
  • Next, we will test for a product that does not exist. Enter the following as the request URL. Click the blue “Send” button.
http://localhost/api/product/read_one.php?id=999

Update product

Create “update.php” file

  • Open product folder.
  • Create a new update.php file.
  • Open that file and put the following code inside it.
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: POST");
header("Access-Control-Max-Age: 3600");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

// include database and object files
include_once '../config/database.php';
include_once '../objects/product.php';

// get database connection
$database = new Database();
$db = $database->getConnection();

// prepare product object
$product = new Product($db);

// get id of product to be edited
$data = json_decode(file_get_contents("php://input"));

// set ID property of product to be edited
$product->id = $data->id;

// set product property values
$product->name = $data->name;
$product->price = $data->price;
$product->description = $data->description;
$product->category_id = $data->category_id;

// update the product
if($product->update()){

    // set response code - 200 ok
    http_response_code(200);

    // tell the user
    echo json_encode(array("message" => "Product was updated."));
}

// if unable to update the product, tell the user
else{

    // set response code - 503 service unavailable
    http_response_code(503);

    // tell the user
    echo json_encode(array("message" => "Unable to update product."));
}
?>

Product update() method

  • Open objects folder.
  • Open product.php file.
  • The previous section will not work without the following code inside the Product class.
// update the product
function update(){

    // update query
    $query = "UPDATE
                " . $this->table_name . "
            SET
                name = :name,
                price = :price,
                description = :description,
                category_id = :category_id
            WHERE
                id = :id";

    // prepare query statement
    $stmt = $this->conn->prepare($query);

    // sanitize
    $this->name=htmlspecialchars(strip_tags($this->name));
    $this->price=htmlspecialchars(strip_tags($this->price));
    $this->description=htmlspecialchars(strip_tags($this->description));
    $this->category_id=htmlspecialchars(strip_tags($this->category_id));
    $this->id=htmlspecialchars(strip_tags($this->id));

    // bind new values
    $stmt->bindParam(':name', $this->name);
    $stmt->bindParam(':price', $this->price);
    $stmt->bindParam(':description', $this->description);
    $stmt->bindParam(':category_id', $this->category_id);
    $stmt->bindParam(':id', $this->id);

    // execute the query
    if($stmt->execute()){
        return true;
    }

    return false;
}

Output

Open POSTMAN. Enter the following as the request URL.

http://localhost/api/product/update.php
  • Click the “Body” tab.
  • Click “raw”.
  • Enter the following JSON value.
  • Make sure the ID exists in your database.
  • Click the blue “Send” button.
{
    "id" : "106",
    "name" : "Amazing Pillow 3.0",
    "price" : "255",
    "description" : "The best pillow for amazing programmers.",
    "category_id" : 2,
    "created" : "2018-08-01 00:35:07"
}

The product ID 106, is just an example. You need to specify a product ID that exists in your database.

If you specify an ID that does not exist in the database, it might still say that the product was updated. It does not update anything on the database but the query was executed successfully without any syntax errors.

To prevent this, you need an extra validation where you check if an ID exists in the database. This feature is not yet part of our tutorial.

  • If updating a product is successful, it should look like this:
  • If the system fails to update the product, the output will look like this:

Delete Product

Create “delete.php” file

  • Open product folder.
  • Create new delete.php file.
  • Open that file and put the following code inside it.
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");
header("Access-Control-Allow-Methods: POST");
header("Access-Control-Max-Age: 3600");
header("Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");

// include database and object file
include_once '../config/database.php';
include_once '../objects/product.php';

// get database connection
$database = new Database();
$db = $database->getConnection();

// prepare product object
$product = new Product($db);

// get product id
$data = json_decode(file_get_contents("php://input"));

// set product id to be deleted
$product->id = $data->id;

// delete the product
if($product->delete()){

    // set response code - 200 ok
    http_response_code(200);

    // tell the user
    echo json_encode(array("message" => "Product was deleted."));
}

// if unable to delete the product
else{

    // set response code - 503 service unavailable
    http_response_code(503);

    // tell the user
    echo json_encode(array("message" => "Unable to delete product."));
}
?>

Product delete() method

  • Open objects folder.
  • Open product.php file.
  • The previous section will not work without the following code inside the Product class.
// delete the product
function delete(){

    // delete query
    $query = "DELETE FROM " . $this->table_name . " WHERE id = ?";

    // prepare query
    $stmt = $this->conn->prepare($query);

    // sanitize
    $this->id=htmlspecialchars(strip_tags($this->id));

    // bind id of record to delete
    $stmt->bindParam(1, $this->id);

    // execute query
    if($stmt->execute()){
        return true;
    }

    return false;
}

Output

Open POSTMAN. Enter the following as the request URL.

http://localhost/api/product/delete.php
  • Click the “Body” tab.
  • Click “raw”.
  • Enter the following JSON value.
  • Make sure the ID exists in your database.
  • Click the blue “Send” button.
{
    "id" : "106"
}
  • If a product was successfully deleted, it should look like this:
  • If the system fails to delete the product, the output will look like this:

Search Products

Create “search.php” file

  • Open product folder.
  • Create a search.php file.
  • Open that file and place the following code.
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");

// include database and object files
include_once '../config/core.php';
include_once '../config/database.php';
include_once '../objects/product.php';

// instantiate database and product object
$database = new Database();
$db = $database->getConnection();

// initialize object
$product = new Product($db);

// get keywords
$keywords=isset($_GET["s"]) ? $_GET["s"] : "";

// query products
$stmt = $product->search($keywords);
$num = $stmt->rowCount();

// check if more than 0 record found
if($num>0){

    // products array
    $products_arr=array();
    $products_arr["records"]=array();

    // retrieve our table contents
    // fetch() is faster than fetchAll()
    // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        // extract row
        // this will make $row['name'] to
        // just $name only
        extract($row);

        $product_item=array(
            "id" => $id,
            "name" => $name,
            "description" => html_entity_decode($description),
            "price" => $price,
            "category_id" => $category_id,
            "category_name" => $category_name
        );

        array_push($products_arr["records"], $product_item);
    }

    // set response code - 200 OK
    http_response_code(200);

    // show products data
    echo json_encode($products_arr);
}

else{
    // set response code - 404 Not found
    http_response_code(404);

    // tell the user no products found
    echo json_encode(
        array("message" => "No products found.")
    );
}
?>

Create search() method

  • Open objects folder.
  • Open product.php file.
  • Add the following search() method.
// search products
function search($keywords){

    // select all query
    $query = "SELECT
                c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created
            FROM
                " . $this->table_name . " p
                LEFT JOIN
                    categories c
                        ON p.category_id = c.id
            WHERE
                p.name LIKE ? OR p.description LIKE ? OR c.name LIKE ?
            ORDER BY
                p.created DESC";

    // prepare query statement
    $stmt = $this->conn->prepare($query);

    // sanitize
    $keywords=htmlspecialchars(strip_tags($keywords));
    $keywords = "%{$keywords}%";

    // bind
    $stmt->bindParam(1, $keywords);
    $stmt->bindParam(2, $keywords);
    $stmt->bindParam(3, $keywords);

    // execute query
    $stmt->execute();

    return $stmt;
}

Output

Open POSTMAN. Enter the following as the request URL.

http://localhost/api/product/search.php?s=shirt

Click the blue “Send” button.

  • If there was a product found, it should look like this:
  • If there are no products found, the output will look like this:

Paginate Products

Create “read_paging.php” file

  • Open product folder.
  • Create read_paging.php file.
<?php
// required headers
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");

// include database and object files
include_once '../config/core.php';
include_once '../shared/utilities.php';
include_once '../config/database.php';
include_once '../objects/product.php';

// utilities
$utilities = new Utilities();

// instantiate database and product object
$database = new Database();
$db = $database->getConnection();

// initialize object
$product = new Product($db);

// query products
$stmt = $product->readPaging($from_record_num, $records_per_page);
$num = $stmt->rowCount();

// check if more than 0 record found
if($num>0){

    // products array
    $products_arr=array();
    $products_arr["records"]=array();
    $products_arr["paging"]=array();

    // retrieve our table contents
    // fetch() is faster than fetchAll()
    // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        // extract row
        // this will make $row['name'] to
        // just $name only
        extract($row);

        $product_item=array(
            "id" => $id,
            "name" => $name,
            "description" => html_entity_decode($description),
            "price" => $price,
            "category_id" => $category_id,
            "category_name" => $category_name
        );

        array_push($products_arr["records"], $product_item);
    }


    // include paging
    $total_rows=$product->count();
    $page_url="{$home_url}product/read_paging.php?";
    $paging=$utilities->getPaging($page, $total_rows, $records_per_page, $page_url);
    $products_arr["paging"]=$paging;

    // set response code - 200 OK
    http_response_code(200);

    // make it json format
    echo json_encode($products_arr);
}

else{

    // set response code - 404 Not found
    http_response_code(404);

    // tell the user products does not exist
    echo json_encode(
        array("message" => "No products found.")
    );
}
?>

Create “core.php” file

This file holds our core configuration like the home URL and pagination variables.

  • Open the config folder.
  • Create core.php file.
  • Open core.php file.
  • Place the following code.
<?php
// show error reporting
ini_set('display_errors', 1);
error_reporting(E_ALL);

// home page url
$home_url="http://localhost/api/";

// page given in URL parameter, default page is one
$page = isset($_GET['page']) ? $_GET['page'] : 1;

// set number of records per page
$records_per_page = 5;

// calculate for the query LIMIT clause
$from_record_num = ($records_per_page * $page) - $records_per_page;
?>

Create “readPaging()” method

  • Open objects folder.
  • Open product.php file.
  • Add the following method inside the product class.
  • This method will return a list of records limited to what we set in $records_per_page of the previous section.
// read products with pagination
public function readPaging($from_record_num, $records_per_page){

    // select query
    $query = "SELECT
                c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created
            FROM
                " . $this->table_name . " p
                LEFT JOIN
                    categories c
                        ON p.category_id = c.id
            ORDER BY p.created DESC
            LIMIT ?, ?";

    // prepare query statement
    $stmt = $this->conn->prepare( $query );

    // bind variable values
    $stmt->bindParam(1, $from_record_num, PDO::PARAM_INT);
    $stmt->bindParam(2, $records_per_page, PDO::PARAM_INT);

    // execute query
    $stmt->execute();

    // return values from database
    return $stmt;
}

Create “count()” method

Still in the product class (product.php file), add the following method. The total rows are needed to build the pagination array. It is included in the ‘paging’ computation.

// used for paging products
public function count(){
    $query = "SELECT COUNT(*) as total_rows FROM " . $this->table_name . "";

    $stmt = $this->conn->prepare( $query );
    $stmt->execute();
    $row = $stmt->fetch(PDO::FETCH_ASSOC);

    return $row['total_rows'];
}

Get “paging” array

  • Create shared folder.
  • Open shared folder.
  • Create utilities.php file.
  • Open utilities.php file and place the following code.
<?php
class Utilities{

    public function getPaging($page, $total_rows, $records_per_page, $page_url){

        // paging array
        $paging_arr=array();

        // button for first page
        $paging_arr["first"] = $page>1 ? "{$page_url}page=1" : "";

        // count all products in the database to calculate total pages
        $total_pages = ceil($total_rows / $records_per_page);

        // range of links to show
        $range = 2;

        // display links to 'range of pages' around 'current page'
        $initial_num = $page - $range;
        $condition_limit_num = ($page + $range)  + 1;

        $paging_arr['pages']=array();
        $page_count=0;

        for($x=$initial_num; $x<$condition_limit_num; $x++){
            // be sure '$x is greater than 0' AND 'less than or equal to the $total_pages'
            if(($x > 0) && ($x <= $total_pages)){
                $paging_arr['pages'][$page_count]["page"]=$x;
                $paging_arr['pages'][$page_count]["url"]="{$page_url}page={$x}";
                $paging_arr['pages'][$page_count]["current_page"] = $x==$page ? "yes" : "no";

                $page_count++;
            }
        }

        // button for last page
        $paging_arr["last"] = $page<$total_pages ? "{$page_url}page={$total_pages}" : "";

        // json format
        return $paging_arr;
    }

}
?>

Output

Open POSTMAN. Enter the following as the request URL.

http://localhost/api/product/read_paging.php

Click the blue “Send” button.

  • If there are products found, scroll down to see the paging node. It should look like this:
  • If there are no products found, the output will look like this:

Read Categories

Create “category.php” file

  • Open objects folder.
  • Create new category.php file.
  • Place the following code inside the category.php file.
<?php
class Category{

    // database connection and table name
    private $conn;
    private $table_name = "categories";

    // object properties
    public $id;
    public $name;
    public $description;
    public $created;

    public function __construct($db){
        $this->conn = $db;
    }

    // used by select drop-down list
    public function readAll(){
        //select all data
        $query = "SELECT
                    id, name, description
                FROM
                    " . $this->table_name . "
                ORDER BY
                    name";

        $stmt = $this->conn->prepare( $query );
        $stmt->execute();

        return $stmt;
    }
}
?>

Create “read.php” file

  • Create new category folder.
  • Open that folder and create new read.php file inside it.
  • Open read.php file and place the following code.
<?php
// required header
header("Access-Control-Allow-Origin: *");
header("Content-Type: application/json; charset=UTF-8");

// include database and object files
include_once '../config/database.php';
include_once '../objects/category.php';

// instantiate database and category object
$database = new Database();
$db = $database->getConnection();

// initialize object
$category = new Category($db);

// query categorys
$stmt = $category->read();
$num = $stmt->rowCount();

// check if more than 0 record found
if($num>0){

    // products array
    $categories_arr=array();
    $categories_arr["records"]=array();

    // retrieve our table contents
    // fetch() is faster than fetchAll()
    // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        // extract row
        // this will make $row['name'] to
        // just $name only
        extract($row);

        $category_item=array(
            "id" => $id,
            "name" => $name,
            "description" => html_entity_decode($description)
        );

        array_push($categories_arr["records"], $category_item);
    }

    // set response code - 200 OK
    http_response_code(200);

    // show categories data in json format
    echo json_encode($categories_arr);
}

else{

    // set response code - 404 Not found
    http_response_code(404);

    // tell the user no categories found
    echo json_encode(
        array("message" => "No categories found.")
    );
}
?>

Add Category “read()” method

  • Open objects folder.
  • Open category.php file.
  • The previous section’s code will not work without the following code inside the category.php file.
  • Add the following method inside the Category class.
// used by select drop-down list
public function read(){

    //select all data
    $query = "SELECT
                id, name, description
            FROM
                " . $this->table_name . "
            ORDER BY
                name";

    $stmt = $this->conn->prepare( $query );
    $stmt->execute();

    return $stmt;
}

Output

Open POSTMAN. Enter the following as the request URL.

http://localhost/api/category/read.php

Click the blue “Send” button.

  • If there are categories found, it should look like this:
  • If there are no categories found, the output will look like this:

Download Source Codes

Choose your download

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Create product✔✔
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Update product✔✔
Delete product✔✔
Search products✔✔
Paginate products✔✔
Read categories✔✔
Delete selected product–✔
Export product CSV–✔
Read products by category–✔
Search products with pagination–✔
Create category–✔
Read categories–✔
Read one category–✔
Update category–✔
Delete category–✔
Search categories–✔
Paginate categories–✔
Delete selected categories–✔
Export categories CSV–✔
Search categories with pagination–✔
Use the buttons below to download. ↓BASICPRO
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What’s Next?

Next, we will learn how to use this API with a user interface made with JavaScript. Let’s learn our JavaScript CRUD tutorial.

Go to next tutorial

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