php + sqlserver

Dbconn

<?php
	class DbConn{
		private $conn;
		private $rs;
		
		private function __construct(){
			$serverName = "localhost"; //数据库服务器地址
			$uid = "sa"; //数据库用户名
			$pwd = "123456"; //数据库密码
			$connectionInfo = array("UID"=>$uid, "PWD"=>$pwd, "Database"=>"user");
			$this->conn = sqlsrv_connect( $serverName, $connectionInfo);
			if($this->conn == false)
			{
			echo "连接失败！";
			die( print_r( sqlsrv_errors(), true));
			}else{
			echo "连接成功！";   
			}
		}
		private function __clone(){}
		public static function getInstance(){
			static $obj;
			if($obj == NULL){
				$obj = new DbConn();
			}
			return $obj;
		} 
		public function exec($sql){
			sqlsrv_query($this->conn,$sql);
			$row = sqlsrv_rows_affected($this->conn);
			return $row;
		}
		public function queryAll($sql){
			$result = array();
			$this->rs = sqlsrv_query($this->conn,$sql);
			while($row = sqlsrv_fetch_array($this->rs)){
				$result[] = $row;
			}
			return $result;
		}
		public function queryOne($sql){
				$result = NULL;
				$this->rs = sqlsrv_query($this->conn,$sql);
				if($row = sqlsrv_fetch_array($this->rs))
					{
						$result = $row;
					}
					return $result;
		}
		public function del($sql){
			$result = NULL;
			$result = sqlsrv_query($this->conn,$sql);
			return $result;
		}
		public function freeResult()
		{
			sqlsrv_free_stmt($this->rs);
		}
		public function close()
		{
			sqlsrv_close($this->conn);
		}
	}