PHP 连接MySQL 的单态类

<?php /** * author: xueming */ class MySQLConnFactory { private $conn; static private $_mysqlconn; //Construct-->connect DB private function __construct($host,$username,$password) { $this->conn = mysql_connect($host,$username,$password); $this->query("SET NAMES 'utf8'"); return $this->conn; } private function __clone(){} public static function getSingleMySQLConn($host,$username,$password) { if(FALSE==(self::$_mysqlconn instanceof self)) { self::$_mysqlconn = new self($host,$username,$password); } return self::$_mysqlconn; } //select DB public function select_db($database) { $this->result = mysql_select_db($database); return $this->result; } //Query public function query($query) { return $this->result = mysql_query($query, $this->conn); } //fetch result public function fetch_array($fetch_array) { return $this->result = mysql_fetch_array($fetch_array, MYSQL_ASSOC); } //close public function close() { return $this->result = mysql_close($this->conn); } } ?>

调用方式如下

$sql = "select * from test"; $connector = MySQLConnFactory::getSingleMySQLConn($db_server,$db_user,$db_pwd); $connector -> select_db($db_name); $result = $connector -> query($sql);