PHP - extending PHP Data Object to add new functionality - php

Question

So this is what I would like to achive.
I would like to use PDO, joust as it is I like it, but I would like to add some new methods on top of PDO.
Like: update(), insert(), delete(), fetchAllAssoc(), etc...
So I would have to work with both PDO and PDO Statement objects from inside one class.
Beacuse to achive update, i would have to build a query, prepare() it, that would return PDO Statement object and then I would have to bindValues and then execute.
This is what I have done so far:
<?php
namespace Database\DBAL;
use PDO;
class Database extends PDO
{
protected static $instance;
public static function getInstance()
{
if(empty(static::$instance))
{
// This will be fetched from config
$dns = "mysql:host=localhost;dbname=db_name";
$username = "root";
$password = "my_pwd";
static::$instance = new Database($dns, $username, $password);
}
return static::$instance;
}
/**
* Detect param type
*/
protected function detectType($value)
{
if(is_string($value))
{
return PDO::PARAM_STR;
}
else if(is_int($value))
{
return PDO::PARAM_INT;
}
else if(is_null($value))
{
return PDO::PARAM_NULL;
}
else if(is_bool($value))
{
return PDO::PARAM_BOOL;
}
else
{
return false;
}
}
/**
* Updates table
*/
public function update($table, $data, $identifier)
{
$set = array();
foreach ($data as $columnName => $columnValue) {
$set[] = $columnName . ' = ?';
}
$query = 'UPDATE ' . $table . ' SET ' . implode(', ', $set) . ' WHERE ' . implode(' = ? AND ', array_keys($identifier)) . ' = ?';
$params = array_merge(array_values($data), array_values($identifier));
array_unshift($params, null);
unset($params[0]);
echo $query;
$pdos = static::$instance->prepare($query);
foreach($params as $key => $param)
{
$pdos->bindValue($key, $param, $this->detectType($param));
}
return $pdos->execute();
}
}
?>
You would use it like this:
use Database\DBAL\Database;
$db = Database::getInstance();
$db->update("users", array("user_password" => "new password"), array("user_id" => 1));
My question is, is this the right way to do it?
I was reading about Decorator and Facade pattern and it dosent look like this.
What is the best way to extend PDO class with my methods that would do simple deletes, inserts and fetch some data? And I want PDO to be intact, so I can use it the way I would usualy do... What pattern should I use and what would be the best way?
Thanks!

Answer 1

If i'm correct you are implementing the active record pattern which is an anti pattern. Please look after for a few ORM framework.
I've created my own: DataContext class which contains all the PDO stuffess (i'm not extending the PDO!), TableEntity classes which handles all the CRUD operations and Entity classes which are "the rows from tables".
$dc = new TestDataContext(...);
$dc->users()->Where(column, 1, '=')->...
$dc->users()->InsertOnSubmit(new User())
$dc->SubmitChanges();
Like Linq to SQL. :-)