Create trigger in Postgres

Question

I have two tables A and B. A has the following columns : a_name, a_num, a_addr. B also has these columns.

Whenever I insert a record in A, I want that record to be inserted in B as well by the use of a trigger.

Answer 1

CREATE OR REPLACE FUNCTION trigger()
  RETURNS trigger AS
$BODY$
begin
if tg_op='INSERT' then
insert into b values (new.a_name ,new.a_num ,new.a_addr);
return new;
end if;
return null;
end;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

---------------------------
CREATE TRIGGER trigger_a
  AFTER INSERT OR UPDATE
  ON a
  FOR EACH ROW
  EXECUTE PROCEDURE trigger();