how to use PDO connection object in different files [duplicate]

Question

Hello i am new to PDO with MYSQL, here are my two files 1) index.php

require_once 'prd.php';
try{
    $db = new PDO ('mysql:host=xxxx;dbname=xxx;charset=utf8', 'xxx', 'xxxx');
    echo 'connectd';
}catch(PDOException $conError){
    echo 'failed to connect DB' . $conError->getMessage ();
}
$conn = new prdinfo();
$conn->con($db);

2) product.php

class prdinfo{function con($db){
    try{
        foreach($db->query("select * from products where vendor_id = 2" ) as $row){
            $prod_id = $row ['product_id'];
            echo '<br/>' . $prod_id;
        }
    }catch(PDOException $ex){
        echo 'an error occured' . $ex->getMessage();
    }
}
}

my problem is here i can pass the connection object to every file, but i have so many files to use database queries, so i need to pass the $bd to all the files. this is getting burden on the code. so is there any way to connect the database with PDO. Thanks

Answer 1

1. pdo.php, taken from here. People often overlook many important connection options, so I had to write a dedicated article that explains how to connect with PDO properly

2. product.php

    <?php
    class prdinfo  
    { 
        function __construct($db)
        {
            $this->db = $db;
        }
   
        function getVendor($vendor)
        {
            $sql = "select * from products where vendor_id = ?";
            $stm = $this->db->prepare($sql);
            $stm->execute(array($vendor));
            return $stm->fetchAll();
        }
    }
   

3. index.php

    <?php
    require 'pdo.php';
    require 'product.php';
   
    $info   = new prdinfo($pdo);
    $vendor = $info->getVendor(2);
    foreach ($vendor as $row)
    {
        echo $row['product_id'];
    }
   

It would be also a good idea to implement class autoloading instead of manually calling require.