ALTER TABLE `old_signature` 
ADD `modify_sign_status` ENUM('approved_add','reject_add','approved_modify','reject_modify','approved_deleted','reject_deleted','pending') NOT NULL AFTER `sign_status`, 
ADD `page_number` INT NOT NULL 
AFTER `modify_sign_status`;


CHANGE `sign_status` `sign_status` ENUM('active','pending_add','pending_modify','pending_delete','deleted','rejected') CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;