create table testtr (a int, b text);

create function testtr_trigger() returns trigger LANGUAGE uplpgsql as

$$begin

raise notice 'tg_op = %', tg_op;

raise notice 'old(%) = %', old.a, row(old.*);

raise notice 'new(%) = %', new.a, row(new.*);

if (tg_op = 'DELETE') then

return old;

else

return new;

end if;

end$$;

create trigger testtr_trigger before insert or delete or update on testtr

for each row execute function testtr_trigger();

insert into testtr values (1, 'one'), (2, 'two');

update testtr set a = a + 1;

delete from testtr;

create table trg_v_t(i int, v text);

create function trg_v_fn() returns trigger language uplpgsql as $$

raise notice '% % % nargs=% arg0=%', tg_when, tg_level, tg_op, tg_nargs, tg_argv[0];

if tg_level = 'ROW' and tg_op = 'DELETE' then return old; end if;

if tg_level = 'ROW' then return new; end if;

return null;

end; $$;

create trigger trg_v_after_row after insert or update or delete on trg_v_t

for each row execute function trg_v_fn('after-row');

create trigger trg_v_stmt after insert on trg_v_t

for each statement execute function trg_v_fn('stmt');

insert into trg_v_t values (1,'a');

update trg_v_t set v = 'b';

delete from trg_v_t;

create trigger trg_v_when before update on trg_v_t

for each row when (old.i is distinct from new.i) execute function trg_v_fn('when');

insert into trg_v_t values (1,'a');

update trg_v_t set v = 'c';

update trg_v_t set i = 2;

drop trigger trg_v_when on trg_v_t;

create view trg_v_view as select * from trg_v_t;

create function trg_v_io() returns trigger language uplpgsql as $$

raise notice 'instead of % on view', tg_op;

return new;

end; $$;

create trigger trg_v_io_t instead of insert on trg_v_view

for each row execute function trg_v_io();

insert into trg_v_view values (9,'z');

create function trg_v_tt() returns trigger language uplpgsql as $$

declare n int;

select count(*) into n from newtab;

raise notice 'transition rows=%', n;

return null;

end; $$;

create trigger trg_v_tt_t after insert on trg_v_t

referencing new table as newtab for each statement execute function trg_v_tt();

insert into trg_v_t values (5,'x'),(6,'y');

create function trg_v_c() returns trigger language uplpgsql as $$

raise notice 'constraint trigger: %', tg_op;

return null;

end; $$;

create constraint trigger trg_v_c_t after insert on trg_v_t

deferrable for each row execute function trg_v_c();

insert into trg_v_t values (7,'q');

drop view trg_v_view;

drop table trg_v_t cascade;

drop function trg_v_fn();

drop function trg_v_io();

drop function trg_v_tt();

drop function trg_v_c();