Creating a database connection class (PDO) and fetch data

Question

I am new to OOP, so I am trying to learn how to create classes and use them. Currently I am trying to fetch data from my MySQL table.

To create the connection with M

Answer 1

IMHO you can just inject the PDO connection into the functions that need it:

<?php

$dbHandle = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
$dbHandle->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
// always disable emulated prepared statement when using the MySQL driver
$dbHandle->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

function get_all($dbHandle) {
    $sql = "SELECT * FROM information";
    $stmt = $dbHandle->prepare($sql);
    $stmt->execute();
    $stmt->setFetchMode(PDO::FETCH_ASSOC);

    return $stmt;
}

get_all($dbHandle);

If you really think you need some class to access to database (other than PDO) (which you don't need) you would have to extend PDO:

<?php

class DBConnection extends PDO
{
    public function __construct()
    {
        parent::__construct("mysql:host=$host;dbname=$dbname", $user, $pass);
        $this->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        // always disable emulated prepared statement when using the MySQL driver
        $this->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
    }
}

$dbHandle = new DBConnection();

function get_all($dbHandle) {
    $sql  = "SELECT * FROM information";
    $stmt = $dbHandle->prepare($sql);
    $stmt->execute();
    $stmt->setFetchMode(PDO::FETCH_ASSOC);

    return $stmt;
}

get_all($dbHandle);

Answer 2

Maybe change the DBConnections FUNCTION to a __contstruct() function. In addition, you'd need to extend the PDO class to use all the methods within it.