php实现的用户查询类实例

<?php class user {  var $usertable;  function get_oneuser($field,$value)  {   $field_array=array("id","name");  //查询方式   if(in_array($field,$field_array))   {    $sql="SELECT * FROM `$this->usertable` WHERE $field='$value'";    $db=new database;    $res=$db->execute($sql);    $obj_user=mysql_fetch_object($res);    return $obj_user;   }   else echo "查询方式不对";  }  function get_moreusers()  {   global $db;   $argnums=func_num_args();   $argarr=func_get_args();   switch($argnums)   {    case 0:     $sql="SELECT * FROM `$this->usertable`";     break;    case 2:     $sql="SELECT * FROM `$this->usertable` WHERE $argarr[0]='$argarr[1]'";     break;    case 4:     $sql="SELECT * FROM `$this->usertable` WHERE $argarr[0]='$argarr[1]' AND $argarr[2]='$argarr[3]'";     break;   }   //$db=new database;   $res=$this->execute($sql);   $obj_arr=array();   while($obj=mysql_fetch_object($res))   {    $obj_arr[]=$obj;   }   return $obj_arr;  } }?>