I was noticing that to update a has_many association, Rails uses the
following:
begin
delete from tagpairs where id = 33;
delete from tagpairs where id = 34;
delete from tagpairs where id = 35;
…
insert into tagpairs (…) values (…);
insert into tagpairs (…) values (…);
…
commit
This would be better as:
delete from tagpairs where obj_type = 'guidepage' and obj_id = 1;
insert into tagpairs (...) values (...);
...
In my case, I’m using a polymorphic association. However, the basic
idea applies to a non-polymorphic association. We can and should delete
members of the association based on the association key field having a
certain value rather than deleting specific ids. Also, notice how this
means that we don’t necessarily have to store the ‘id’ field, which, for
my application, is redundant.
Cs