ALTER TABLE `qs_Post`
  DROP `authorType`,
  DROP `authorId`;

ALTER TABLE `qs_PostComment`
  DROP `authorId`,
  DROP `authorType`;

ALTER TABLE `qs_Post` ADD `createdById` INT NULL AFTER `id`;
ALTER TABLE `qs_Post` ADD INDEX(`createdById`);
ALTER TABLE `qs_Post` ADD FOREIGN KEY (`createdById`) REFERENCES `qs_Admin`(`id`) ON DELETE SET NULL ON UPDATE CASCADE;

ALTER TABLE `qs_PostComment`
  ADD `createdBy` ENUM('admin','user') NULL AFTER `idPost`,
  ADD `createdById` INT NULL DEFAULT NULL AFTER `createdBy`;