how i can prevent multiple time connected to database - php

Question

here is my code
pdo.php
class Connection {
public function __construct() {
$this->connect ($db);
}
private function connect($db) {
try {
if (! $db){
$this->db = new PDO ( 'mysql:host=localhost;dbname=Shopping;charset=utf8', 'xxxx', 'xxxxx' );
echo 'Connected';
return $this->db;
}
catch ( PDOException $conError ) {
echo 'failed to connect DB' . $conError->getMessage ();
}
}
}
product.php
class ProductInsert extends Connection { //here my function is called multiple times
function __construct() {
parent::__construct($db);
}
public function prdInsert(.....)
{ ........}
here my problem is database connection is opened multiple time. when ever i am calling the productInsert() then database connection is opened how i can prevent this

Answer 1

Do not extend your application class from database class.
This is your main problem.
They are too different classes having nothing in common.
So you have to just use your db object as a property.
Connection class is also useless at the moment, as it's just a leaky disguise for the PDO.
So, just create raw PDO object and then pass it in the constructor of product
class ProductInsert
{
function __construct(PDO $db)
{
$this->db = $db;
}
public function prdInsert(.....)
}
And for goodness sake, learn to indent your code.

Answer 2

class Connection {
public function __construct($db) {
return $this->connect($db);
}
private function connect($db) {
try {
if (! $db){
$db = new PDO ( 'mysql:host=localhost;dbname=Shopping;charset=utf8', 'xxxx', 'xxxxx' );
echo 'new connection';
}
return $db;
}
catch ( PDOException $conError ) {
echo 'failed to connect DB' . $conError->getMessage ();
}
}
}

Answer 3

here is the solution
pdo.php
class Connection {
// Declare instance
private static $instance = NULL;
// the constructor is set to private so so nobody can create a new instance using new
private function __construct() {
// maybe set the db name here later
}
// Return DB instance or create intitial connection #return object (PDO) #access public
public static function getInstance() {
if (! self::$instance) {
self::$instance = new PDO ( 'mysql:host=localhost;dbname=Shopping;charset=utf8', 'root', 'vss0ftech' );
self::$instance->setAttribute ( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
echo 'connected';
} else
echo 'connection is already existed';
return self::$instance;
}
// Like the constructor, we make __clone private so nobody can clone the instance
PRIVATE FUNCTION __CLONE() {
}
}
product.php
here we can call the method as like this
class ProductInsert {
public function prdInsert(.....) {
$result_By_Vendor_And_Title = Connection::getInstance ()->query ( "select * from........)
}
}