feat: introduce updated_at column (#9)

Co-authored-by: Thomas <31189692+ecktoteckto@users.noreply.github.com>

Author: kevcodez

db/migrations/0003_updated_at.sql

@@ -0,0 +1,37 @@
+create
+or replace function orb.set_updated_at () returns trigger language plpgsql as $$
+begin
+  new.updated_at = now();
+  return NEW;
+end;
+$$;
+
+alter function orb.set_updated_at () owner to postgres;
+
+alter table orb.subscriptions
+add updated_at timestamptz default timezone ('utc'::text, now()) not null;
+
+create trigger handle_updated_at before
+update on orb.subscriptions for each row
+execute function orb.set_updated_at ();
+
+alter table orb.customers
+add updated_at timestamptz default timezone ('utc'::text, now()) not null;
+
+create trigger handle_updated_at before
+update on orb.customers for each row
+execute function orb.set_updated_at ();
+
+alter table orb.invoices
+add updated_at timestamptz default timezone ('utc'::text, now()) not null;
+
+create trigger handle_updated_at before
+update on orb.invoices for each row
+execute function orb.set_updated_at ();
+
+alter table orb.credit_notes
+add updated_at timestamptz default timezone ('utc'::text, now()) not null;
+
+create trigger handle_updated_at before
+update on orb.credit_notes for each row
+execute function orb.set_updated_at ();