封装链接数据库

<?php

class mysql{
private $host ;
private $user = "root";

private $pwd = "";
private $db = "bbs";
private $charset =
"utf8";
private $conn = "";

public function
__construct($host="127.0.0.1",$user="root",$pwd="",$db="bbs",$charset="utf8"){

$this->host = $host;
$this->user = $user;

$this->pwd = $pwd;
$this->db = $db;

$this->charset = $charset;
$this->conn = get_conn();

}

public function get_conn(){
//像下面这种写代码的方式，一般俗称
硬代码
//好的程序习惯是，可以设置为变量，那么一定要设置为变量
//可以设置为常量，那么最好设置为常量
//
mysql_connect("127.0.0.1","root","root");

$conn = mysql_connect($this->host,$this->user,$this->pwd) or
die(mysql_error());
mysql_select_db($this->db,$this->conn);

mysql_query("set names ‘$this->charset‘");

return $conn;
}

public function myquery($sql){
$result =
mysql_query($sql);
return $result;
}

public function delete($sql){

$this->myquery($sql);
return mysql_affected_rows();
//如果执行删除成功,那么肯定有受影响的行数
// return $result;
}

public function insert($sql){

}
}

$mysql = new
mysql("127.0.0.1","root","","bbs","utf8");
//$mysql->host =
"127.0.0.1";

?>