PDO :: __ construct

PHP PDO Reference Manual

PDO :: __ construct - Creates a PDO instance database connection (PHP 5> = 5.1.0, PECL pdo> = 0.1.0)

Explanation

grammar

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

Creates a request to connect to the database connection to the database PDO instance.

Parameter Description

• dsn: Data Source Name or so-called DSN, contains the information required to connect to the database.
• username: DSN string username. For some PDO drivers, this parameter is optional.
• password: DSN string password. For some PDO drivers, this parameter is optional.
• driver_options: a key driver specific connection options => value array.

return value

Error / exception

If you try to connect to the requested database fails, the PDO :: __ construct () throws an exception PDO (PDOException).

Examples

Create a PDO instance by calling the driver

<?php
/* 通过调用驱动程序创建一个PDO实例 */
$dsn = 'mysql:dbname=testdb;host=127.0.0.1';
$user = 'dbuser';
$password = 'dbpass';

try {
    $dbh = new PDO($dsn, $user, $password);
} catch (PDOException $e) {
    echo 'Connection failed: ' . $e->getMessage();
}

?>

PHP PDO Reference Manual