PHP data processing public class

  /*======================================== ===========================*/
 /* File name: BaseLogic.class.php */
 /* Summary: Data processing public Class. */

 class BaseLogic extends MyDB {
 protected $tabName; //The name of the table
 protected $fieldList; //Field collection
 protected $messList;

 //============ ===============================
 // Function: add($postList)
 // Function: Add
 // Parameters: $postList Submitted variable list
 // Return: The newly inserted auto-increment ID
 //============================ ==============
 function add($postList) {
 $fieldList='';
 $value='';
 foreach ($postList as $k=>$v) {
 if(in_array($k, $this->fieldList)){
 $fieldList.=$k.",";
 if (!get_magic_quotes_gpc())
 $value .= "'".addslashes($ v)."',";
 else
 $value .= "'".$v."',";
 }
 }

 $fieldList=rtrim($fieldList, ",");
 $value= rtrim($value, ",");

 $sql = "INSERT INTO {$this->tabName} (".$fieldList.") VALUES(".$value.")";
 echo $sql;
 $result=$this->mysqli->query($sql);
 if($result && $this->mysqli->affected_rows >0 )
 return $this->mysqli-> insert_id;
 else
 return false;
 }


 //==================================== =======
 // Function: mod($postList)
 // Function: Modify table data
 // Parameter: $postList submitted variable list
 //============ ===============================
 function mod($postList) {
 $id=$postList["id"] ;
 unset($postList["id"]);
 $value='';
 foreach ($postList as $k=>$v) {
 if(in_array($k, $this->fieldList) ){
 if (!get_magic_quotes_gpc())
 $value .= $k." = '".addslashes($v)."',";
 else
 $value .= $k." = '".$ v."',";
 }
 }
 $value=rtrim($value, ",");
 $sql = "UPDATE {$this->tabName} SET {$value} WHERE id={$id }";
 return $this->mysqli->query($sql);
 }

 //======================== ==================
 // Function: del($id)
 // Function: Delete
 // Parameter: $id number or ID list array
 // Return : 0 Failure and success are the number of deleted records
 //======================================== ====
 function del($id) {
 if(is_array($id))
 $tmp = "IN (" . join(",", $id) . ")";
 else
 $tmp = "= $id";

 $sql = "DELETE FROM {$this->tabName} WHERE id " . $tmp ;
 return $this->mysqli->query($sql);

 }


 function get($id) {
 $sql = "SELECT * FROM {$this->tabName} WHERE id ={$id}";

 $result=$this->mysqli->query( $sql);

 if($result && $result->num_rows ==1){
 return $result->fetch_assoc();
 }else{
 return false;
 }

 }
 function getMessList( ){
 $message="";
 if(!empty($this->messList)){
 foreach($this->messList as $value){
 $message.=$value." }
 }
 return $message;
 }
 }
 ?>

php