我有数据库连接代码:
define('DBDRIVER', 'mysql');
define("DBHOST", "localhost");
define("DBNAME", "dbname");
define("DBUSER", "username");
define("DBPASS", "password");
$dboptions = array(
PDO::ATTR_PERSISTENT => FALSE,
PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8',
);
try {
$PDO = new PDO(DBDRIVER . ':host=' . DBHOST . ';dbname=' . DBNAME, DBUSER, DBPASS, $dboptions);
$PDO -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$PDO -> setAttribute(PDO::ATTR_EMULATE_PREPARES, FALSE);
} catch(PDOException $e) {
echo "Connection failed: " . $e -> getMessage();
}
并上课。
如何在班上使用PDO变量? 我可以使用全局变量但不能在课堂上工作吗? 有没有系统在类中使用这个PDO变量(不要为PDO连接定义任何类或构造函数)?
答案 0 :(得分:1)
class MyDb{
public $pdo;
private static $instance;
public function __construct(PDO $pdo){
$this->pdo = $pdo;
}
public static function getInstance()
{
if (!isset(self::$instance))
{
$object = __CLASS__;
self::$instance = new $object;
}
return self::$instance;
}
}
$ query = MyDb :: getInstance() - > pdo-> query('SELECT * FROM ...');