1:protected//定义私有函数,只可以被同一包中的类所访问
2:public//定义公共函数
3:self::$ins//调用当前类的静态方法,自 PHP 5.3.0 后可用$this例:
<?php //单例模式的数据库连接 class dbClassManage { protected static $ins=null; public static function getIns($hosts,$users,$pwd,$dbname){ if (self::$ins === null) { self::$ins = new self($hosts,$users,$pwd,$dbname); } return self::$ins; } public $conn; /* $hosts:服务器主机地址 $users:服务器登录用户名 $pwd:服务器登录密码 $dbname:数据库名称 */ // final防继承 final protected function __construct($hosts,$users,$pwd,$dbname) { //连接mysql数据库 $this->conn = mysql_connect($hosts,$users,$pwd); if($this->conn == false) exit("服务器连接失败"); //设置编码 $c = mysql_query("set names utf8",$this->conn); if($c == false) exit("编码设置有误"); $f = mysql_select_db($dbname,$this->conn); if($f == false) exit("数据库连接失败"); } //防克隆 final protected function __clone() { } /* *增、删、改 */ public function exeSql($sql) { mysql_query($sql,$this->conn); return true; } /* *关闭数据库 */ public function close() { return mysql_close($this->conn); } /* *查询一条数据 */ public function getOneData($sql,$mode = MYSQL_ASSOC) { $result = mysql_query($sql,$this->conn); $rs = mysql_fetch_array($result,$mode); mysql_free_result($result); return $rs; } /* *查询多条数据 */ public function getMoreData($sql,$mode = MYSQL_ASSOC) { $result = mysql_query($sql,$this->conn); while($res = mysql_fetch_array($result,$mode) or false) { $rs[] = $res; } mysql_free_result($result); return $rs; } } //$db = new dbClassManage('localhost','root','','dsshop'); $db = dbClassManage::getIns('localhost','root','','dsshop'); ?>