begin;

alter table ttrss_user_entries change feed_id feed_id integer null;

alter table ttrss_user_entries add column orig_feed_id integer;
update ttrss_user_entries set orig_feed_id = NULL;

alter table ttrss_user_entries add constraint FOREIGN KEY (orig_feed_id) REFERENCES ttrss_feeds(id) ON DELETE SET NULL;

update ttrss_version set schema_version = 60;

commit;