a:5:{i:0;s:3:"PID";i:1;s:3:"UID";i:2;s:3:"Num";s:3:"_pk";s:3:"PID";s:5:"_type";a:3:{s:3:"PID";s:7:"int(11)";s:3:"UID";s:7:"int(11)";s:3:"Num";s:12:"varchar(500)";}}