封装的一个DB。 欢迎大家前来指导批评````haha。

<?php
/****************************
* Author : 假.装.幸.福
*/
define('DB_VERSION','1.0');
Class DB{
public $queryid;
public $user,$userpw,$host,$dbname,$prefix;

public function connect( $host,$user,$userpw,$dbname)
{
  $this->host = $host;
  $this->user = $user;
  $this->userpw = $userpw;
  $this->dbname = $dbname;  
  if(!@mysql_connect($this->host,$this->user,$this->userpw)){   
   exit("用户名或密码错误！");
  }
  $this->selectdb($this->dbname);   
}
    public function selectdb()
{     
     if(!@mysql_select_db($this->dbname)){
      exit("数据库选择失败或数据不存在！");
     }
    }
     
    public function query( $sql )
{
     //echo $this->UpPrefix($sql);
     return mysql_query($this->UpPrefix($sql));
    }
        
    public function SetNames( $names )
{
     $this->names = $names;
     mysql_query("set names $this->names");
    }
           
    public function SetPrefix( $prefix )
{
     $this->prefix = $prefix;   
    }   
    public function UpPrefix($str)
{
    return $this->UpPrefix = str_replace([url=mailto:]'#@__',$this->prefix,$str[/url]);
    }
   
     public function SetTable( $tablename )
  {
      $this->table = $tablename;
     }
     
    public function SetFields( $fields = '*' )
{
     if(empty($fields)){$fields = '*';}
     $this->fields = $fields;
    }
    public function SetWhere( $wherestr='' )
{
     if(empty($wherestr)){exit("SetWhere()中需要设置操作的条件!");}
     $this->where = " Where ".$wherestr;
    }
public function SetOrder( $orderid='',$order='Desc' )
{
  if(empty($orderid)){exit("Setorder()中必须设置一个字段名");}
  $this->order = " Order by ".$orderid." ".$order;
}
public function SetLimit( $limit = '' )
{
  if(empty($limit)){exit("SetLimit()中必须设置一个参数!");}
  $this->limit = " Limit ".$limit;
}
   
    public function GetRow( $sql )
{     
     return mysql_fetch_array($this->query($sql));  
    }
   
    public function GetArray( $query )
{     
     return mysql_fetch_array($query);  
    }
    Public function GetNums($sql)
{         
     return mysql_num_rows($this->query($sql));
    }
Public function Insert( $data = array() )
{
   global $prefix;
  foreach ($data as $key => $value){ $namestr  .= "`".$key."`".","; $valuestr .= "'".$value."'".","; }
         $namestr = substr($namestr,0,-1);
         $valuestr = substr($valuestr,0,-1);
         $insert_sql = "Insert into {$prefix}$this->table ($namestr) VALUES ($valuestr)";
         if(!@$this->query($insert_sql)){exit("执行时出现异常!");}
         return mysql_insert_id();        
}
Public function Update( $data = array() )
{
   global $prefix;
  foreach ($data as $key => $value){ $valuestr .= $key.'='."'".$value."'".","; }
  $valuestr = substr($valuestr,0,-1);
  $update_sql = "Update {$prefix}$this->table Set $valuestr $this->where";  
  if(!@$this->query($update_sql)){exit("执行时出现异常!");}
}
Public function Delete()
{
  global $prefix;
  $delete_sql = "Delete From {$prefix}$this->table $this->where";
  if(!@$this->query($delete_sql)){exit("执行时出现异常！");}
}
}
?>