Create a database connection using OOP PHP [with example and explanation ] 2022

Ok so create a class called DB or any other name you prefer, DB for basically database so that you know why you created this class.

<?php

namespace services;

use mysqli;

class DB
{
    public $db_host = 'localhost';
    public $db_user = 'root';
    public $db_password = 'awesomemanu';
    public $db_database = 'react_php';



    public function database()
    {
        $conn = new mysqli($this->db_host, $this->db_user, $this->db_password, $this->db_database);


        // Check connection
        if ($conn->connect_error) {
        die("Connection failed: " . $conn->connect_error);
        }

        //echo "Connected successfully";
        return $conn;
    }
}

Here you can see we have a connection now in any php file when ever you want to use this connection call it like this

<?php


namespace Api\Controllers;


use Services\DB;


class PostsController
{
    public $conn = null;



    public function __construct()
    {
        // Create connection
        $this->conn = (new DB())->database();
    
    }

Now $this-conn has the database.

Use in your queries

    public function savePostsToDatabase($posts)
    {        
        
        // Check connection
        if ($this->conn->connect_error) {
            die("Connection failed: " . $this->conn->connect_error);
        }


        $sql = "INSERT INTO posts (firstname, lastname, email)
        VALUES ('John', 'Doe', 'john@example.com')";



        if (mysqli_query($this->conn, $sql)) {                      // Here we used it.
            echo "New record created successfully";
        } else {
            echo "Error: " . $sql . "<br>" . mysqli_error($this->conn);
        }
        
        mysqli_close($this->conn);


    }

Hope this helps