<?php
/**
* Db Class
*
* Database interaction with help from PDO
*
* @copyright 2009
* @version 1.0
* @author Alex
*/
class Db
{
private static $_instance = NULL;
private function __construct() {
// can not call me
}
private function __clone() {
// no!
}
public static function getInstance() {
if (!self::$_instance)
{
try {
self::$_instance = new PDO('mysql:host=' . CONFIG_MYSQL_SERVER . ';dbname=' . CONFIG_MYSQL_DATABASE, CONFIG_MYSQL_USERNAME, CONFIG_MYSQL_PASSWORD);;
self::$_instance-> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch(PDOException $e) {
trigger_error($e->getMessage());
}
}
return self::$_instance;
}
public static function query($query /*string*/, $bindings = NULL)
{
$queryPortion = substr($query,0, 6);
try {
if ($bindings) {
$prepared = self::getInstance()->prepare($query);
foreach($bindings as $binding=>$data) { // defaults to string
if (!is_array($data)) {
$prepared->bindParam($binding, $data);
} else {
switch(count($data)) {
case 1:
$prepared->bindParam($binding, $data['value']);
break;
case 2:
$prepared->bindParam($binding, $data['value'], $data['dataType']);
break;
case 3:
$prepared->bindParam($binding, $data['value'], $data['dataType'], (int)$data['length']);
break;
default:
trigger_error('An error has occured with the prepared statement bindings.');
return false;
break;
}
}
}
$prepared->execute();
return $prepared->fetchAll(PDO::FETCH_ASSOC);
} else if (String::match($queryPortion, 'select')) { // if this is a select query
$rows = self::getInstance()->query($query);
return $rows->fetchAll(PDO::FETCH_ASSOC);
} else {
return self::getInstance()->exec($query);
}
}
catch(PDOException $e)
{
trigger_error($e->getMessage());
}
}
public static function getLastInsertId()
{
try {
self::getInstance()->lastInsertId();
}
catch(PDOException $e)
{
trigger_error($e->getMessage());
}
}
public static function disconnect()
{
// kill PDO object
self::$_instance = NULL;
}
}
Refactorings
No refactoring yet !
Gregor
February 25, 2010, February 25, 2010 16:20, permalink
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Nice job. Here is my very similiar approach with little options on the queries.
<?php
class Database {
private static $dbh = null;
private static function connect() {
try {
self::$dbh = new PDO('mysql:dbname='.DB_NAME.';host=localhost', USER, PASS, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'"));
self::$dbh->setAttribute (PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
self::$dbh->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);
} catch (PDOException $e) {
self::close_db();
throw new Exception($e->getMessage());
}
return self::$dbh;
}
public static function close_db() {
self::$dbh = null;
}
public static function prepare($queryString) {
try {
$db_handle = self::connect();
$dbh = $db_handle->prepare($queryString);
return $dbh;
} catch(PDOException $e) {
throw new Exception($e->getMessage());
self::close_db();
}
}
public static function execute($stmt, $parametri = null) {
try {
$stmt->execute($parametri);
} catch(PDOException $e) {
throw new Exception($e->getMessage());
self::close_db();
}
}
public static function getAll($stmt, $parametri = null, $fetch = PDO::FETCH_ASSOC) {
try {
self::execute($stmt, $parametri);
$result = $stmt->fetchAll($fetch);
} catch(PDOException $e) {
throw new Exception($e->getMessage());
self::close_db();
}
return $result;
}
public static function LastId()
{
try {
self::connect()->lastInsertId();
}
catch(PDOException $e)
{
throw new Exception($e->getMessage());
}
}
public static function getFirst($stmt,$parametri = null, $fetch = PDO::FETCH_ASSOC) {
try {
self::execute($stmt, $parametri);
$result = $stmt->fetch($fetch);
} catch(PDOException $e) {
throw new Exception($e->getMessage());
self::close_db();
}
return $result;
}
}
?>
I was looking for an easy way to do queries and get their results... This is what I came up with but any refactorings would be greatly appreciated. I'm still a beginner with OO. I pass a keyed array to do prepared queries.