The PDO class

Введение

Represents a connection between PHP and a database server.

Class synopsis

PDO

PDO {

__construct ( string $dsn [, string $username [, string $password [, array $driver_options ]]] )

bool beginTransaction ( void )

bool commit ( void )

mixed errorCode ( void )

array errorInfo ( void )

int exec ( string $statement )

mixed getAttribute ( int $attribute )

array getAvailableDrivers ( void )

string lastInsertId ([ string $name= NULL ] )

PDOStatement prepare ( string $statement [, array $driver_options= array() ] )

PDOStatement query ( string $statement )

string quote ( string $string [, int $parameter_type= PDO::PARAM_STR ] )

bool rollBack ( void )

bool setAttribute ( int $attribute , mixed $value )

}

Содержание

PDO::beginTransaction — Initiates a transaction
PDO::commit — Commits a transaction
PDO::__construct — Creates a PDO instance representing a connection to a database
PDO::errorCode — Fetch the SQLSTATE associated with the last operation on the database handle
PDO::errorInfo — Fetch extended error information associated with the last operation on the database handle
PDO::exec — Execute an SQL statement and return the number of affected rows
PDO::getAttribute — Retrieve a database connection attribute
PDO::getAvailableDrivers — Return an array of available PDO drivers
PDO::lastInsertId — Returns the ID of the last inserted row or sequence value
PDO::prepare — Prepares a statement for execution and returns a statement object
PDO::query — Executes an SQL statement, returning a result set as a PDOStatement object
PDO::quote — Quotes a string for use in a query.
PDO::rollBack — Rolls back a transaction
PDO::setAttribute — Set an attribute

Large Objects (LOBs)

PDO::beginTransaction

PDO

PHP Manual

User Contributed Notes
PDO

kcleung at kcleung dot no-ip dot org
02-May-2010 10:47

Here is an singleton PDO example:

                

                ###### config.ini ######

                db_driver=mysql

                db_user=root

                db_password=924892xp

                

                [dsn]

                host=localhost

                port=3306

                dbname=localhost

                

                [db_options]

                PDO::MYSQL_ATTR_INIT_COMMAND=set names utf8

                

                [db_attributes]

                ATTR_ERRMODE=ERRMODE_EXCEPTION

                ############

                

                <?php class Database {

                    private static $link = null ;

                

                    private static function getLink ( ) {

                        if ( self :: $link ) {

                            return self :: $link ;

                        }

                

                        $ini = _BASE_DIR . "config.ini" ;

                        $parse = parse_ini_file ( $ini , true ) ;

                

                        $driver = $parse [ "db_driver" ] ;

                        $dsn = "${driver}:" ;

                        $user = $parse [ "db_user" ] ;

                        $password = $parse [ "db_password" ] ;

                        $options = $parse [ "db_options" ] ;

                        $attributes = $parse [ "db_attributes" ] ;

                

                        foreach ( $parse [ "dsn" ] as $k => $v ) {

                            $dsn .= "${k}=${v};" ;

                        }

                

                        self :: $link = new PDO ( $dsn, $user, $password, $options ) ;

                

                        foreach ( $attributes as $k => $v ) {

                            self :: $link -> setAttribute ( constant ( "PDO::{$k}" )

                                , constant ( "PDO::{$v}" ) ) ;

                        }

                

                        return self :: $link ;

                    }

                

                    public static function __callStatic ( $name, $args ) {

                        $callback = array ( self :: getLink ( ), $name ) ;

                        return call_user_func_array ( $callback , $args ) ;

                    }

                } ?>


                <?php // examples
 $stmt = Database :: prepare ( "SELECT 'something' ;" ) ;
 $stmt -> execute ( ) ;
 var_dump ( $stmt -> fetchAll ( ) ) ;
 $stmt -> closeCursor ( ) ;
 ?>

Megaloman
18-Feb-2009 03:03

"And storing username/password inside class is not a very good idea for production code."

                

                Good idea is to store database connection settings in *.ini files but you have to restrict access to them. For example this way:

                

                my_setting.ini:

                [database]

                driver = mysql

                host = localhost

                ;port = 3306

                schema = db_schema

                username = user

                password = secret

                

                Database connection:

                <?php
 class MyPDO extends PDO
 {

                    public function __construct($file = 'my_setting.ini')

                    {

                        if (!$settings = parse_ini_file($file, TRUE)) throw new exception('Unable to open ' . $file . '.');

                       

                        $dns = $settings['database']['driver'] .

                        ':host=' . $settings['database']['host'] .

                        ((!empty($settings['database']['port'])) ? (';port=' . $settings['database']['port']) : '') .

                        ';dbname=' . $settings['database']['schema'];

                       

                        parent::__construct($dns, $settings['database']['username'], $settings['database']['password']);

                    }

                }
 ?>


                Database connection parameters are accessible via human readable ini file for those who screams even if they see one PHP/HTML/any_other command.

anrdaemon at freemail dot ru
22-Aug-2008 08:16

Keep in mind, you MUST NOT use 'root' user in your applications, unless your application designed to do a database maintenance.

                

                And storing username/password inside class is not a very good idea for production code. You would need to edit the actual working code to change settings, which is bad.

schizo_mind at hotmail dot com
28-Jul-2008 05:00

<?php
 class PDOConfig extends PDO {

                   

                    private $engine;

                    private $host;

                    private $database;

                    private $user;

                    private $pass;

                   

                    public function __construct(){

                        $this->engine = 'mysql';

                        $this->host = 'localhost';

                        $this->database = '';

                        $this->user = 'root';

                        $this->pass = '';

                        $dns = $this->engine.':dbname='.$this->database.";host=".$this->host;

                        parent::__construct( $dns, $this->user, $this->pass );

                    }

                }
 ?>