Example of transparent soft-deletes in Postgres

soft_delete_postgres.sql

create table widget_history (
  id bigint generated always as identity,
  name text not null,
  created_at timestamp not null default current_timestamp,
  deleted_at timestamp
);

create index widget_by_name on widget_history(name) where deleted_at is null;

create view widget as
  select * from widget_history where deleted_at is null;
  
create or replace function soft_delete()
returns trigger as $$
declare
    target_tbl   text;
    update_query text;
begin
	target_tbl := tg_table_name || '_history';
    update_query := format(
        'update %I set deleted_at = current_timestamp where id = $1',
        target_tbl
    );
    execute update_query using old.id;
    return null;
end;
$$ language plpgsql;

create trigger widget_soft_delete_trigger
    instead of delete on widget
    for each row
    execute function soft_delete();

---

insert into widget (name)
values ('Thungummy'), ('Whatchamacallit');

select * from widget;
--  id |      name       |         created_at         | deleted_at
-- ----+-----------------+----------------------------+------------
--   1 | Thingummy       | 2025-09-16 17:49:39.177458 |
--   2 | Whatchamacallit | 2025-09-16 17:49:56.544898 |
-- (2 rows)

delete from widget where name like 'What%';

select * from widget;
--  id |      name       |         created_at         | deleted_at
-- ----+-----------------+----------------------------+------------
--   1 | Thingummy       | 2025-09-16 17:49:39.177458 |
-- (1 row)select * from widget;

select * from widget_history;
--  id |      name       |         created_at         | deleted_at
-- ----+-----------------+----------------------------+---------------------------
--   1 | Thingummy       | 2025-09-16 17:49:39.177458 |
--   2 | Whatchamacallit | 2025-09-16 17:49:56.544898 | 2025-09-16 18:38:26.842889
-- (2 rows)