PHP database operation model class (using __call method)

 "", "order" => "", "limit" => "", "group" => "", "having" => "" ); public function __construct($tableName){ $this -> tableName = $tableName; try{ $this -> link = mysqli_connect(HOSTNAME,USERNAME,PASSWORD,DATANAME); mysqli_set_charset($this -> link,"UTF8"); }catch(Exception $e){ echo "数据库连接失败"; } $this -> desc(); } public function __destruct(){ mysqli_close($this -> link); } public function desc(){ $sql = " desc {$this -> tableName}; "; $res = mysqli_query($this -> link,$sql); $arr = mysqli_fetch_all($res,MYSQLI_ASSOC); for($i = 0 ;$i < count($arr);$i++){ $brr[] = $arr[$i]['Field']; } $this -> zd = $brr; return $brr; } public function __call($name,$value){ $name = strtolower($name); if(array_key_exists($name,$this -> method)){ if($name == 'order'){ $this -> method['order'] = " order by ".$value[0]; }elseif($name == 'group'){ $this -> method['group'] = " group by ".$value[0]; }else{ $this -> method[$name] = " {$name} ".$value[0]; } }else{ return "the method is not found!"; } return $this; } public function method(){ return " {$this -> method['where']} {$this -> method['order']} {$this -> method['limit']} {$this -> method['group']} {$this -> method['having']}; "; } public function find($a="*"){ if(in_array("{$a}",$this -> zd) || $a == "*"){ $sql = "select {$a} from {$this -> tableName} {$this -> method()} "; }else{ $sql = "select * from {$this -> tableName}"; } //return $sql; $res = mysqli_query($this -> link,$sql); $arr = mysqli_fetch_all($res,MYSQLI_ASSOC); return $arr; } }

 where("name = 'zhu'")->limit("5,10"); var_dump($a -> find("name"));