How to Create REST API Using Vanilla PHP

API stands for Application Programming Interface.

It’s an intermediary that allows two applications to talk to each other by both delivering requests to the provider and getting back a response.

REST stands for Representational State Transfer

See How to work with Fetch API

In this tutorial, we are going to demonstrate how to create a REST API in our software application using PHP.

We are going to create an API with a GET Request. We want to retrieve registration details from our database.

1. Setup the Database

First, we need to setup our table. We will create our table as follows

CREATE TABLE `your_database_name`.`test_registration` ( `id` INT NOT NULL AUTO_INCREMENT , `username` VARCHAR(255) NOT NULL , `email` VARCHAR(255) NOT NULL , `password` TEXT NOT NULL , `date_time` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP , PRIMARY KEY (`id`)) ENGINE = MyISAM;

2. Add Mock Data

Next, we are going add sample data to our table so that we can have something to retrieve.

INSERT INTO `test_registration` (`id`, `username`, `email`, `password`, `date_time`) VALUES (NULL, 'Luke', '[email protected]', '123333', current_timestamp());

3. Create the API

Next, we are going to write the API that will fetch our records from the database.

What we want to do first is to write a database connection script and we’re using PDO. We’ve covered much about PDO here.

We’re fetching the result and we’re storing it in an array and encoding with JSON.

 <?php

header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Headers: access");
header("Access-Control-Allow-Methods: GET");
header("Content-Type: application/json; charset=UTF-8");

class Constants
{
    static $DB_SERVER="localhost";
    static $DB_NAME="your_database_name";
    static $USERNAME="your_database_username";
    static $PASSWORD="your_database_password";

    static $SQL_SELECT_ALL="SELECT * FROM test_registration ORDER BY RAND()";

}

class Register
{

    public function connect()
    {
        $con=new mysqli(Constants::$DB_SERVER,Constants::$USERNAME,Constants::$PASSWORD,Constants::$DB_NAME);
        if($con->connect_error)
        {
            return null;
        }else
        {
            return $con;
        }
    }
    public function select()
    {
        $con=$this->connect();
        if($con != null)
        {
            $result=$con->query(Constants::$SQL_SELECT_ALL);
            if($result->num_rows>0)
            {
                $reg=array();
                while($row=$result->fetch_array())
                {
                    array_push($reg, array("id"=>$row['id'],"email"=>$row['email'],"username"=>$row['username']));
                }
                print(json_encode(array_reverse($reg)));
            }else
            {
                print(json_encode(array("No records found")));
            }
            $con->close();

        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
    }
}
$reg=new Register();
$reg->select();

?>

Result:

Conclusion

This is how we create API using vanilla PHP.