在 php 类中定义方法 连接数据库

public function __db(){
global $_G;

$link = mysql_connect("localhost","root","4b907287b4");
//连接
mysql_select_db('hs_discuz_bbs');
//选择数据库
//mysql_query("SET NAMES 'utf8'");
//设置编码（需要和本页面的编码一致
//$query1 = "select count(*) from "


$sql = "select max(id) as maxid from url_log";
//echo "71" .$sql;
$get_list_res = mysql_query($sql ,$link);

$maxid =1;
while($recs = mysql_fetch_array($get_list_res)) {
$maxid = $recs["maxid"] + 1;
}

$query = "insert into url_log(id, username, url) values('".$maxid."','".$_G['uid']."', '".$_SERVER['HTTP_REFERER']."')";
//$query = "insert into url_log(id, username, url) values('1','username','aa')";
mysql_query($query,$link);
  /************************
   * 自己的代码 
   ************************/

/* 关闭连接 */ 
  mysql_close($link); 
}