<?
class db{
var $linkid;
var $sqlid;
var $record;
function db($host="",$username="",$password="",$database="")
{
if(!$this->linkid)  @$this->linkid = mysql_connect($host, $username, $password) or die("连接服务器失败.");
@mysql_select_db($database,$this->linkid) or die("无法打开数据库");
return $this->linkid;}
function query($sql)
{if($this->sqlid=mysql_query($sql,$this->linkid)) return $this->sqlid;
else {
  $this->err_report($sql,mysql_error);
return false;}
}
function nr($sql_id="")
{if(!$sql_id) $sql_id=$this->sqlid;
return mysql_num_rows($sql_id);}
function nf($sql_id="")
{if(!$sql_id) $sql_id=$this->sqlid;
return mysql_num_fields($sql_id);}
function nextrecord($sql_id="")
{if(!$sql_id) $sql_id=$this->sqlid;
if($this->record=mysql_fetch_array($sql_id))  return $this->record;
else return false;
}
function f($name)
{
if($this->record[$name]) return $this->record[$name];
else return false;
}
function close() {mysql_close($this->linkid);}
function lock($tblname,$op="WRITE")
{if(mysql_query("lock tables ".$tblname." ".$op)) return true; else return false;}
function unlock()
{if(mysql_query("unlock tables")) return true; else return false;}
function ar() {
    return @mysql_affected_rows($this->linkid);
  }
function i_id() {
  return mysql_insert_id();
}
function err_report($sql,$err)
{
echo "Mysql查询错误<br>";
echo "查询语句：".$sql."<br>";
echo "错误信息：".$err;
}
/****************************************类结束***************************/
}?> 