PDO 类

(PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)

简介

代表 PHP 和数据库服务之间的一个连接

类摘要

PDO {

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

bool beginTransaction ( void )

bool commit ( void )

mixed errorCode ( void )

public array errorInfo ( void )

int exec ( string $statement )

mixed getAttribute ( int $attribute )

static array getAvailableDrivers ( void )

bool inTransaction ( void )

string lastInsertId ([ string $name = NULL ] )

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

public PDOStatement query ( string $statement )

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

bool rollBack ( void )

bool setAttribute ( int $attribute , mixed $value )

}

PDO::beginTransaction — 启动一个事务
PDO::commit — 提交一个事务
PDO::__construct — 创建一个表示数据库连接的 PDO 实例
PDO::errorCode — 获取跟数据库句柄上一次操作相关的 SQLSTATE
PDO::errorInfo — Fetch extended error information associated with the last operation on the database handle
PDO::exec — 执行一条 SQL 语句，并返回受影响的行数
PDO::getAttribute — 取回一个数据库连接的属性
PDO::getAvailableDrivers — 返回一个可用驱动的数组
PDO::inTransaction — 检查是否在一个事务内
PDO::lastInsertId — 返回最后插入行的ID或序列值
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 — 回滚一个事务
PDO::setAttribute — 设置属性

用户评论:

[#1] sideshowAnthony at googlemail dot com [2015-07-23 23:54:23]

Here is a cheeky PDO helper class to get you started . . .

define('DB_MAIN', 'localhost|user1|pa55word|db1');

// Connect to database db1
$db = new my_db(DB_MAIN);

// Request "SELECT * FROM table1 WHERE a=16 AND b=22"
// Get an array of stdClass's
$rows = $db->fetchAll('SELECT * FROM table1 WHERE a=? AND b=?', 16, 22);

class my_db{

private static $databases;
private $connection;

public function __construct($connDetails){
if(!is_object(self::$databases[$connDetails])){
list($host, $user, $pass, $dbname) = explode('|', $connDetails);
$dsn = "mysql:host=$host;dbname=$dbname";
self::$databases[$connDetails] = new PDO($dsn, $user, $pass);
}
$this->connection = self::$databases[$connDetails];
}

public function fetchAll($sql){
$args = func_get_args();
array_shift($args);
$statement = $this->connection->prepare($sql);
$statement->execute($args);
return $statement->fetchAll(PDO::FETCH_OBJ);
}
}

[#2] rumsg at mail dot ru [2015-05-05 12:33:10]

$DB = new PDO('mysql:host=127.0.0.1;port=3306;dbname=anexis_new;charset=UTF8;','root','password', array(PDO::ATTR_PERSISTENT=>true));
$DB->query("SET NAMES utf8;");

[#3] thz at plista dot com [2013-06-14 13:25:45]

Starting with PHP 5.4 you are unable to use persistent connections when you have your own database class derived from the native PDO class. If your code uses this combination, you will encounter segmentation faults during the cleanup of the PHP process.
You can still use _either_ a derived PDO class _or_ persistent connections.

For more information, please see this bug report: https://bugs.php.net/bug.php?id=63176

[#4] williambarry007 at gmail dot com [2011-10-12 13:10:27]

PDO and Dependency Injection

Dependency injection is good for testing. But for anyone wanting various data mapper objects to have a database connection, dependency injection can make other model code very messy because database objects have to be instantiated all over the place and given to the data mapper objects.

The code below is a good way to maintain dependency injection while keeping clean and minimal model code.

<?php class DataMapper { public static $db; public static function init($db) { self::$db = $db; } } class VendorMapper extends DataMapper { public static function add($vendor) { $st = self::$db->prepare( "insert into vendors set first_name = :first_name, last_name = :last_name" ); $st->execute(array( ':first_name' => $vendor->first_name, ':last_name' => $vendor->last_name )); } } // In your bootstrap $db = new PDO(...); DataMapper::init($db); // In your model logic $vendor = new Vendor('John', 'Doe'); VendorMapper::add($vendor); ?>

[#5] kcleung at kcleung dot no-ip dot org [2010-05-02 15:47:51]

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 ( ) ; ?>

[#6] Megaloman [2009-02-18 07:03:48]

"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.

[#7] anrdaemon at freemail dot ru [2008-08-22 01:16:27]

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.

[#8] schizo_mind at hotmail dot com [2008-07-28 10:00:16]

<?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 ); } } ?>

PDO 类

简介

类摘要

Table of Contents

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