PDO::__construct

PHP PDO Reference Manual

PDO::__construct — Creates a PDO instance representing a database connection (PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)

Description

Syntax

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

Creates a PDO instance representing a database connection to the requested database.

Parameters

• dsn: Data source name, or DSN, contains the information required to connect to the database.
• username: Username in the DSN string. This parameter is optional for some PDO drivers.
• password: Password in the DSN string. This parameter is optional for some PDO drivers.
• driver_options: A key=>value array of driver-specific connection options.

Return Values

Errors/Exceptions

If the attempt to connect to the requested database fails, PDO::__construct() throws a PDOException.

Examples

Create a PDO instance via driver invocation

<?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