Consiglio PDOSingleton

aragonesse

Consiglio PDOSingleton

Ciao ragazzi,

oggi stavo partorendo una classe Factory per PDO capace di implementare il Sigleton anche su tutti i metodi della classe PDO passando poi l'oggetto PDO
creato alla classe PDOStatement.

Vorrei innanzi tutto sapere cosa ne pensate del codice della classe e del interfaccia e in secondo luogo se secondo la vostra esperienza gli attributi,
ad esempio la gestione delle eccezione, è meglio metterli prima di ritornare
l'stanza della classe al interno del Singleton (dove li ho commentati adesso)
o dopo avere creato l'istanza con il comando:

[php]
$objPDO = PDOFactory::getInstance();
[/php]

P.S. I parametri che formano il DSN li prendo per comodità da un namespace incluso nella index.php

//->class.IPDOFactory.php
[php]
<?php

/**
*

   ProjectName        :        FastCMS

   ProjectAuthor    :        Adriano Giovannini

```
   ProjectMail        :        ...
```

   ProjectFile        :        class_IPDOFactory.php

   ProjectPackage    :        library\PDOFactory

   ProjectLicense    :        GPL V3. Se license\<yourLanguage>\license.tx

                           for more details

*/

interface IPDOFactory
{

/**
 *
 *    Singleton Method
 *
 *    @return bool $_blSingletonInstance
 *
 */
public static function getInstance();

/**
 *
 *    Initiate a transaction
 *
 *    @return bool
 *
 */
public function beginTransaction();    

/**
 *
 *    Commit a transaction
 *
 *    @return bool
 *
 */
public function commit();

/**
 *
 *    Fetch the state of SQL associated whit the last operation on the database
 *
 *    @return string
 *
 */
public function errorCode();
    
/**
 *
 *    Fetch the extended error information associated with the last operation on
 *    database
 *
 *    @return array
 *
 */
public function errorInfo();

/**
 *
 *    Execute SQL statement and return the number of affected row
 *
 *    @param string $PDOStatement
 *
 */
public function exec($PDOStatement);

/**
 *
 *    Retrieve a database connection attribute
 *
 *    @param int $PDOAttribute
 *
 *    @return int
 *
 */
public function getAttribute($PDOAttribute);

/**
 *
 *    Return an array of available PDO Drivers
 *
 *    @return array
 *
 */
public function getAvailableDriver();

/**
 *
 *    Return the ID of the last inserted row
 *
 *    @param string $LastInsertIdName
 *
 *    @return string
 *
 */
public function lastInsertId($LastInsertIdName);

/**
 *
 *    Prepare a statemet for execution and return a PDOStatement object
 *
 *    @param string $PDOStatement
 *    @param array  $PDODriverOptions
 *    
 *    @return $PDOStatement
 *
 */
public function prepare($PDOStatement, $PDODriverOptions = false);

/**
 *
 *    Execute a SQL Statement and returning result set a PDOStatement object
 *
 *    @param string $PDOStatement
 *
 *    @return object $PDOStatement
 *
 */
public function query($PDOStatement);

/**
 *
 *    Execute Query and return all rows in assoc array
 *
 *    @param string $PDOStatement
 *
 *    @return array
 *
 */
public function queryFetchAllAssoc($PDOStatement);

/**
 *
 *    Execute Query and return one rows in assoc array
 *
 *    @param string $PDOStatement
 *
 *    @return array
 *
 */
public function queryFetchRowAssoc($PDOStatement);

/**
 *
 *    Execute Query and select one column only
 *
 *    @param string $PDOStatement
 *
 *    @return mixed
 *
 */
public function queryFetchColAssoc($PDOStatement);

/**
 *
 *    Quote a string for prevent sql injection
 *
 *    @param string $InputString
 *    @param int    $ParameterType
 *
 *    @return string
 *
 */
public function quote($InputString, $ParameterType);

/**
 *
 *    Rolls back a transaction
 *
 *    @return bool
 *
 */
public function rollBack();

/**
 *
 *    Set attribute
 *
 *    @param int      $PDOAttribute
 *    @param mixed $PDOAttributeValue
 *
 *    @return bool
 *
 */
public function setAttribute($PDOAttribute, $PDOAttributeValue);

}

?>
[/php]

//-> class_PDOFactory.php

[php]
<?php

require_once 'class_IPDOFactory.php';

/**
*

   ProjectName        :        FastCMS

   ProjectAuthor    :        Adriano Giovannini

```
   ProjectMail        :        ...
```

   ProjectFile        :        class_PDOFactory.php

   ProjectPackage    :        library\PDOFactory

   ProjectLicense    :        GPL V3. Se license\<yourLanguage>\license.tx

                           for more details

*/
class PDOFactory implements IPDOFactory
{

/**
 *
 *    PDOConnection params
 *    
 * @param strind $_strDSN
 * @param strung $_strUsernme
 * @param string $_strPassword
 *
 */
private static $_strDSN         = PDONS\DSN;
private static $_strUsername    = PDONS\USERNAME;
private static $_strPassword      = PDONS\PASSWORD;

/**
 *
 *    Singleton Instance
 *
 *    @param bool
 *
 */
private static $_blSingletonInstance = null;

/**
 *
 *    Preventi construct and cloning creation
 *
 */
private function __construct()
{

    trigger_error ( "Construct is not allowed" . E_USER_ERROR );
    
}

private function __clone()
{

    trigger_error ( "Clone is not allowed" . E_USER_ERROR );
    
}

/**
 *
 *    Singleton Method
 *
 *    @return bool $_blSingletonInstance
 *
 */
public static function getInstance()
{

    try
    {
    
        if ( self::$_blSingletonInstance == null )
        {
    
        self::$_blSingletonInstance = new PDO ( self::$_strDSN, self::$_strUsername, self::$_strPassword, array(PDO::ATTR_PERSISTENT => true) );
                                                        
        }
        // $objPDO->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        return self::$_blSingletonInstance;
    
    } catch ( PDOException $e ) {
    
        die ( "Error: " . $e->getMessage() );
        
     }
     
}

/**
 *
 *    Initiate a transaction
 *
 *    @return bool
 *
 */
public function beginTransaction()
{

    return self::$_blSingletonInstance->beginTransection();
    
}

/**
 *
 *    Commit a transaction
 *
 *    @return bool
 *
 */
public function commit()
{
    
    return self::$_blSingletonInstance->commit();
    
}

/**
 *
 *    Fetch the state of SQL associated whit the last operation on the database
 *
 *    @return string
 *
 */
public function errorCode()
{

    return self::$_blSingletonInstance->errorCode();
    
}

/**
 *
 *    Fetch the extended error information associated with the last operation on
 *    database
 *
 *    @return array
 *
 */
public function errorInfo()
{

    return self::$_blSingletonInstance->errorInfo();
    
}

/**
 *
 *    Execute SQL statement and return the number of affected row
 *
 *    @param string $PDOStatement
 *
 */
public function exec($PDOStatement)
{

    return self::$_blSingletonInstance->exec($PDOStatement);
    
}

/**
 *
 *    Retrieve a database connection attribute
 *
 *    @param int $PDOAttribute
 *
 *    @return int
 *
 */
public function getAttribute($PDOAttribute)
{

    return self::$_blSingletonInstance->getAttribute($PDOAttribute);
    
}

/**
 *
 *    Return an array of available PDO Drivers
 *
 *    @return array
 *
 */
public function getAvailableDriver()
{

    return self::$_blSingletonInstance->getAvailableDriver();
    
}

/**
 *
 *    Return the ID of the last inserted row
 *
 *    @param string $LastInsertIdName
 *
 *    @return string
 *
 */
public function lastInsertId($LastInsertIdName)
{

    return self::$_blSingletonInstance->lastInsertId($LastInsertIdName);
    
}

/**
 *
 *    Prepare a statemet for execution and return a PDOStatement object
 *
 *    @param string $PDOStatement
 *    @param array  $PDODriverOptions
 *    
 *    @return $PDOStatement
 *
 */
public function prepare($PDOStatement, $PDODriverOptions = false)
{

    if (!$PDODriverOptions)
    {
    
        $PDODriverOptions = array();
        
    }
    return self::$_blSingletonInstance->prepare($PDOStatement, $PDODriverOptions);
    
}

/**
 *
 *    Execute a SQL Statement and returning result set a PDOStatement object
 *
 *    @param string $PDOStatement
 *
 *    @return object $PDOStatement
 *
 */
public function query($PDOStatement)
{

    return self::$_blSingletonInstance->query($PDOStatement);
    
}

/**
 *
 *    Execute Query and return all rows in assoc array
 *
 *    @param string $PDOStatement
 *
 *    @return array
 *
 */
public function queryFetchAllAssoc($PDOStatement)
{

    return self::$_blSingletonInstance->query($PDOStatement)->fetchAll(PDO::FETCH_ASSOC);
    
}

/**
 *
 *    Execute Query and return one rows in assoc array
 *
 *    @param string $PDOStatement
 *
 *    @return array
 *
 */
public function queryFetchRowAssoc($PDOStatement)
{

    return self::$_blSingletonInstance->query($PDOStatement)->fetch(PDO::FETCH_ASSOC);
    
}

/**
 *
 *    Execute Query and select one column only
 *
 *    @param string $PDOStatement
 *
 *    @return mixed
 *
 */
public function queryFetchColAssoc($PDOStatement)
{

    return self::$_blSingletonInstance->query($PDOStatement)->fetchColumn();
    
}

/**
 *
 *    Quote a string for prevent sql injection
 *
 *    @param string $InputString
 *    @param int    $ParameterType
 *
 *    @return string
 *
 */
public function quote($InputString, $ParameterType)
{

    return self::$_blSingletonInstance->quote($InputString, $ParameterType);
    
}

/**
 *
 *    Rolls back a transaction
 *
 *    @return bool
 *
 */
public function rollBack()
{

    return self::$_blSingletonInstance->rollBack();
    
}

/**
 *
 *    Set attribute
 *
 *    @param int      $PDOAttribute
 *    @param mixed $PDOAttributeValue
 *
 *    @return bool
 *
 */
public function setAttribute($PDOAttribute, $PDOAttributeValue)
{

    return self::$_blSingletonInstance->setAttribute($PDOAttribue, $PDOAttributeValue);
    
}

}

?>
[/php]

//-> class_PDOFactoryException.php
[php]
<?php

/**
*

```
   ProjectMail        :        ...
```

   ProjectFile        :        class_PDOFactoryException.php

   ProjectPackage    :        library\PDOFactory

   ProjectLicense    :        GPL V3. Se license\<yourLanguage>\license.tx

                           for more details

*/

class PDOFactoryException
{

public static function PDOExceptionDisplay ( $objPDO, $e, $objStatement)
{

    /**
     *        Static method
     */
    echo "An error occurred connecting: " . $e->getMessage() . "<br />";
        /**
         *        List PDOErrorInfo 
         */
        list ($intErrorCode1, $intErrorCode2, $strErrorInfo) = $objPDO->errorInfo();
            print "PDOExceptionError<br />";
            print "Error Code: '$intErrorCode1'<br />";
            print "Driver Code: '$intErrorCode2'<br />";
            print "Error Info: '$strErrorInfo'<br />";
            
            /**
             *        Check error for PDOStatement class
             */
            if ($objStatement instanceof PDOStatement)
            {
            
                /**
                 *        Print PDOStatement error
                 */
                list ($intErrorCode1, $intErrorCode2, $strErrorInfo) = $objStatement->errorInfo();
                print "PDOStatementExceptoinError<br />";
                print "Error Code: '$intErrorCode1'<br />";
                print "Driver Code: '$intErrorCode2'<br />";
                print "Error Info: '$strErrorInfo'<br />";
                
            }
            exit();
            
}

}

?>
[/php]

//-> PDONamespace.php
[php]
<?php

namespace PDONS
{

const DSN         = 'mysql:host=localhost;charset=utf8;dbname=forum';
const USERNAME      = 'tuauser';
const PASSWORD      = 'tuapass';

}

?>
[/php]

//-> index.php
[php]
<?php

require_once 'PDONamespace.php';
require_once 'library\PDOFactory\class_PDOFactory.php';

try
{

$objPDO = PDOFactory::getInstance();
$objPDO->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    //-> Inizio test PDO
$i = 0;
$strQuery = "SELECT * FROM user";
$objStatement = $objPDO->prepare($strQuery);
$objStatement->execute();
// Rimuovere dai metodi della classe singleton le costanti nel fetch
while ($arRow = $objStatement->fetch(PDO::FETCH_ASSOC))
{
    print "Row $i";
    foreach ($arRow as $key => $value)
    {    
        print " - Column $key, value $value<br />";
    }
    $i++;
}    
//-> PDO Test

} catch ( PDOException $e ) {

require_once 'library\PDOFactory\class_PDOFactoryException.php';
PDOFactoryException::PDOExceptionDisplay ($objPDO, $e, $objStatement);

} catch ( Excpetion $e ) {

die ( "An error occurred: " . $e->getMessage() );

}

?>
[/php]

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