PHP链接数据库--常用的类

<?php
/*
 * 数据库连接类
 */
class DBconnect{
	var $host; 
	var $user; 
	var $passwd; 
	var $database;
	var $conn; 
	//利用构造函数实现变量初始化 
	//同时连接数据库操作
	function DBconnect($host,$user,$password,$database){
		$this->host = $host;
		$this->user = $user;
		$this->passwd = $password;
		$this->database = $database;
		$this->conn=mysql_connect($this->host, $this->user,$this->passwd) or die("Could not connect to $this->host");
		mysql_select_db($this->database,$this->conn) or die("Could not switch to database $this->database");
		mysql_query("set names 'utf8'");
	}
	//该函数用来关闭数据库连接
	function Close(){
		mysql_close($this->conn);
	}
	//该函数实现数据库查询操作
	function Query($string){
		$res = mysql_query($string,$this->conn) or die("Could not query database");
		return $res;
	}
	//该函数返回记录集
	function getRows($res){
		$rowno = 0;
		$rowno = mysql_num_rows($res);
		if($rowno>0){
			for ($row=0;$row<$rowno;$row++){
				$rows[$row]=MySQL_fetch_assoc($res);
			}
			return $rows;
		}
	}
	//该函数取回数据库记录数
	function getRowsNum($res){
		$rowno = 0;
		$rowno = mysql_num_rows($res);
		return $rowno;
	}
}
?>

这是自己常用的一种，