简易封装PDO_MySQL

Pdo_Mysql.php

<?php
/**
 * Pdo MySql driver wrap
 *
 * @category   Class
 * @package    Fasthold Own PHP Snippet
 * @copyright  Copyright (c) 2007 
 * @license    New BSD License
 * @author     Fasthold Lau ([email protected])
 */


/**
 * @example: 
 *
 * $db = new Pdo_Mysql(array('host'=>'localhost','username'=>'root','password'=>'','dbname'=>'uker_access'));
 * $data = $db->fetchAll("select * from pe_article limit 10");
 * print_r($data);
 *
 *
 */
class Pdo_Mysql {
	
	protected $_params;
	
	/**
	 * PDO Object
	 *
	 * @var PDO
	 */
	private $_connection;
	
	/**
	 * Initialize
	 *
	 * @param array $params
	 * @return PDO
	 */
	public function __construct(array $params) {
		$this->_params = $params;
		$this->getConnection($this->_params);
	}
	
	/**
	 * Get the connection object
	 *
	 * @return PDO
	 */
	public function getConnection() {
		if($this->_connection === null) {
			$connectionOptions = array();
			if(empty($this->_params['charset'])) {
				$this->_params['charset'] = 'utf8';
			}
			
			if(! $this->_connection = new PDO(
					'mysql:host='.$this->_params['host'].';dbname='.$this->_params['dbname'].'',
					$this->_params['username'],
					$this->_params['password'],
					array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES {$this->_params['charset']}")) ) {
				throw new PDOException("Can't connect to database");
			}
		}
		return $this->_connection;
	}
	
	/**
	 * Fetch data set
	 *
	 * @param string $sql
	 * @return array
	 */
	public function fetchAll($sql) {
		$stmt = $this->exec($sql);
		if($stmt instanceof PDOStatement) {
			return $stmt->fetchAll();
		} else {
			return false;
		}
	}

	/**
	 * Fetch column data
	 *
	 * @param string $sql
	 * @return array
	 */
	public function fetchColumn($sql) {
		$stmt = $this->exec($sql);
		return current($stmt->fetch());
	}
	
	/**
	 * Fetch only one row data
	 *
	 * @param string $sql
	 * @return array
	 */
	public function fetchRow($sql) {
		$stmt = $this->exec($sql);
		if(false === $stmt) {
			return array();
		}
		return $stmt->fetch(PDO::FETCH_ASSOC);
	}
	
	/**
	 * Execute a SQL statement
	 *
	 * @param string $sql
	 * @return PDOStatement
	 */
	public function exec($sql) {
		$stmt = $this->prepare($sql);
		$stmt->execute();
		return $stmt;
	}
	
	/**
	 * Prepare statement
	 *
	 * @param string $sql
	 * @return PDOStatement
	 */
	public function prepare($sql) {
		$stmt = $this->_connection->prepare($sql);
		return $stmt;
	}
	
	/**
	 * Quote string
	 *
	 * @param string $sql
	 * @return string
	 */
	public function quote($str) {
		return $this->_connection->quote($str);
	}
}