/**
  * Get definition of specifique table
  *
  * @param $table The name of table
  * @return array
  * @author Wilker
  **/
 public function __get($table)
 {
     if (!isset($this->tables[$table])) {
         $this->tables[$table] = DbCommand::table_fields($table);
     }
     return $this->tables[$table];
 }