Best way to implement database connection in php - php

Question

I don't know my method is correct for connecting to the database in php.
Here is the method i am used.
1.created a db_functions.php file.
db_functions.php
/*----for connecting db----*/
function db_connect(){
$connect=new PDO('mysql:host=localhost;dbname=keralalotteryapp','root','');
$connect->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
return $connect;
}
function get_student_data(){
$con=db_connect();
//rest of my query
}
function get_marks($id){
$con=db_connect();
//rest of my query
}
2.In every my page i've included this and call the functions like this way
<?php
require 'db_functions.php';
get_student_data();
get_marks($id);
?>
But everytime call the functions get_student_data() and get_marks() it will again call the db_connect function.
So this is right way to do this?

Answer 1

Create a connection class in a Connection.php file :-
class Connection{
public static $PDO =null;
public static function getConnectionInstance()
{
try{
$PDO = new PDO('mysql:host=localhost;dbname=keralalotteryapp','root','');
return $PDO;
}catch(PDOException $e)
{
die($e->getMessage());
}
}
}
or use this class any other php file like that :-
require_once './Connection.php';
function __construct() {
$this->dbh = Connection::getConnectionInstance();
}
create construct or call static method of connection call

Answer 2

There are many ways to manage database connections, I've seen a global connection object, I've seen some people do connection factories, at the end of the day it really comes down to your needs in your specific application.
That being said, if you have the support for it, I have always been a fan of a closure-based setup as I find it becomes easy to write clean code.
function execute_in_db_context($callback) {
$connect=new PDO('mysql:host=localhost;dbname=keralalotteryapp','root','');
$connect->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$callback($connect);
$connect=null; //cleanup because we can
}
execute_in_db_context(function ($db_connection) {
//blah blah
});