封装访问数据库的类

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     host,$this->uid,$this->pwd,$db);15         //2.判断连接是否出错16         !mysqli_connect_error() or die("连接失败！");17         //3.执行SQL语句18         $result = $dbconnect->query($sql);19         20         if($type==0)21         {22             return $result->fetch_all();23         }24         else25         {26             return $result;27         }28     }29 }